PL/I metamodel

ABSTRACT

A method of and a system for processing an enterpise an application request on an end user application and an application server. This is accomplished by initiating the application request on the end user application in a first language (such as a markup language) with a first application program (such as a Web browser), and transmitting the application request to the server and converting the application from the first language of the first end user application to a language running on the application server, processing the application request on the application server, and transmitting the response from the application server back to the end user application, and converting the response from the language running on the application server to the language of the end user application. The end user application and the application server have at least one connector between them, and the steps of (i) converting the application request from the language of the end user application (as a source language) to the language running on the application server (as a target language), and (ii) converting the response to the application request from the language running on the application server (as a source language) to the language of the end user application (as a target language), each include the steps of invoking connector metamodels of the respective source and target languages, populating the connector metamodels with metamodel data of each of the respective source and target languages, and converting the source language to the target language.

CROSS REFERENCE TO RELATED APPLICATION

This applications claims the benefit under Title 35, United States Code,Sections 111(b) and 119(e), related to Provisional Patent Applications,of the filing date of U.S. Provisional Patent Application Ser. No.60/223,671 filing Aug. 8, 2000 of Steven A. Brodsky and Shyh-Mei F. Hofor EAI Common Application Metamodel.

This application is also related to the following United States PatentApplications, filed on even date herewith:

-   COMMON APPLICATION METAMODEL by Shyh-Mei Ho, Stephen Brodsky, and    James Rhyne; a pending application filed on May 4, 2001 and assigned    application Ser. No. 09/849,107.-   COBOL METAMODEL by Shyh-Mei Ho, Nick Tindall, James Rhyne, Tony    Tsai, Peter Elderon, and Shahaf Abileah; a pending application filed    on May 4, 2001 and assigned application Ser. No. 09/849,813.-   HIGH LEVEL ASSEMBLER METAMODEL by Shyh-Mei Ho, John Ehrman, Benjamin    Sheats, and Jenny Hung; an application filed on May 4, 2001 and    assigned application Ser. No. 09/849,190, and having issued on Aug.    10, 2004 as U.S. Pat. No 6,775,680.-   TYPE DESCRIPTOR METAMODEL by Shyh-Mei Ho, James Rhyne, Peter    Elderon, Nick Tindall, and Tony Tsai; a pending application filed on    May 4, 2001 and assigned application Ser. No. 09/849,377.-   IMS TRANSACTION MESSAGES METAMODEL by Shyh-Mei Ho and Shahaf    Abileah; a pending application filed on May 4, 2001 and assigned    application Ser. No. 09/849,816.-   IMS-MFS (MESSAGE FORMAT SERVICE) METAMODEL by Shyh-Mei Ho, Benjamin    Sheats, Elvis Haicrombe, and Chenhuei J. Chiang; a pending    application filed on May 4, 2001 and assigned application Ser. No.    09/849,105.-   CICS-BMS (BASIC MESSAGE SERVICE) METAMODEL by Shyh-Mei Ho, Andy    Krasun, and Benjamin Sheats; a pending application filed on May 4,    2001 and assigned application Ser. No. 09/849,793.

FIELD OF THE INVENTION

The invention relates to exchanging instructions and/or data betweenapplications to signal readiness to transfer, exchange, or process data,or to establish at least one or more parameters for transferring databetween the applications, and controlling the parameters in order tofacilitate data transfer and communication. The invention furtherrelates to integrating dissimilar applications one executing within oneplatform and another executing in another platform, e.g., multiplecomputers, multiple operating systems, multiple application components,multiple development environments, multiple deployment environments, ormultiple testing and processing, establishing a dialog (e.g., anegotiation) with one another in order to establish connectivity fortransferring data and/or instructions between the applications so as tofacilitate performing tasks on the data or portions thereof toaccomplish an overall goal. The parameters may include one or more offormat, data types, data structures, or commands.

BACKGROUND

The growth of e-business has created a significant need to integratelegacy applications and bring them to the Internet This is because thecurrent trend for new applications is to embrace Web standards thatsimplify end user application construction and scalability. Moreover, asnew applications are created, it is crucial to seamlessly integrate themwith existing systems while facilitating the introduction of newbusiness processes and paradigms.

Integrating new applications with existing applications is especiallycritical since industry analysts estimate that more than seventy percentof corporate data, including data highly relevant to e-commerce, liveson mainframe computers. Moreover, while many e-commerce transactions areinitiated on Windows, Mac, and Linux end user platforms, using a varietyof Web browsers, and go through Windows NT and Unix servers, they areultimately completed on mainframe computers, running mainframeapplications, and impacting data stored in mainframe databases.

There are e-business pressures to integrate server level applicationsand bring them to the Internet. However, there is no complete and easymechanism to integrate or e-business enable the applications.Integration, whether through messaging, procedure calls, or databasequeries, is key to solving many of today's business problems.

Integrating legacy applications with new software is a difficult andexpensive task due, in large part, to the need to customize eachconnection that ties together two disparate applications. There is nosingle mechanism to describe how one application may allow itself to beinvoked by another.

One consequence is an e-commerce environment of multiple applications,developed by multiple development teams, running on different platforms,with different data types, data structures, commands, and commandsyntax's. This environment is stitched together with application programinterfaces and connectors. Connectors are an essential part of the totalapplication framework for e-commerce. Connectors match interfacerequirements of disparate applications and map between disparateinterfaces.

This growing interconnection of old and new software systems andapplications, has led to various middle ware applications and connectorapplications, interface specifications, interface definitions, and code,especially for the interconnection and interaction of markup languages(such as HTML, XML, Dynamic HTML, WML, and the like), through objectoriented languages such as SmallTalk and C++, with languages of legacyapplication server applications (such as PL/I and COBOL). Theseinterface specifications, definitions, and code should apply acrosslanguages, tools, applications, operating systems, and networks so thatan end user experiences the look, feel, and responses of a single,seamless application at her terminal. Instead, the proliferation ofstandards, protocols, specifications, definitions, and code, e.g.,Common Object Request Broker (CORBA), Common Object Model (COM), ObjectLinking and Embedding (OLE), SOM, ORB Plus, Object Broker, Orbix, hasinstead created an e-commerce “Tower of Babel.”

Examples of application integration are ubiquitous: from installing anERP system, to updating an Operational Data Store (ODS) with IMStransactions or invoking CRM systems from MQSeries; each of theserequires the same basic steps. First, a user must find the entity shewants to communicate with, then she must figure out how to invoke theentity, and finally she must provide translation from one nativerepresentation to another. Today, these steps usually require manualinvestigation and hand coding—and leave the developers with a rat's-nestof hard-to-maintain connections between applications.

Attempts to remedy this situation involve application program interfacesand connectors, which are frequently built on Interface DefinitionLanguages. Interface Definition Languages are declarative, definingapplication program interfaces, and, in some cases, issues such as errorhandling. Most Interface Definition Languages are a subset of C++, andspecify a component's attributes, the parent classes that it inheritsfrom, the exceptions that it raises, the typed events that it emits, themethods its interface supports, input and output parameters, and datatypes. The goal of Interface Definition Languages within connectors isto enable collaboration between dissimilar applications without hardcoded application program interfaces.

Ideally, the interface definition language, and the connector of whichit is a part, should facilitate full run-time software applicationcollaboration through such features as

-   -   Method invocation with strong type checking,    -   Run-time method invocation with greater flexibility and run time        binding,    -   High level language binding, with the interface separated from        the implementation.    -   An interface repository containing real time information of        server functions and parameters.

Additionally, the connector and its interface definition language,should be fast, efficient, scalable, portable, support metaclasses,support syntactic level extensions, and support semantic levelextensions.

SUMMARY OF THE INVENTION

The problems associated with integrating new applications, for example,e-commerce applications, with legacy applications are obviated by theCommon Application Metamodel tool, method, and system described herein.The Common Application Metamodel method, tool, and system of theinvention facilitate tooling solutions, data translation, andcommunication and collaboration between dissimilar and disparateapplications, as well as full run-time software applicationcollaboration through an interface with the application server interfacedomain. This is accomplished through metadata interchange information,method invocation with strong type checking, run-time method invocation,run time binding, and high level language binding, with the interfaceseparated from the implementation, and an interface repositorycontaining real time information of client and server interfaceparameters.

Additionally, the tool, method, and system of the invention providefast, efficient, and scalable interconnectivity independently of anytool or middleware, are reusable and portable, and support metaclasses,syntactic level extensions, and semantic level extensions, and areindependent of any particular tool or middleware.

The Common Application Metamodel tool, method, and system is especiallyuseful for providing a data transformer that is bi-directional between aclient application and a server application, transmitting commands anddata both ways between, for example, a Java, HTML, XML, C, or C++application and a PL/I application.

One embodiment of the invention is a method of processing a transactionon or between an end user application and one or more applicationservers. The method comprises the steps of initiating the transaction onthe end user application in a first language with a first applicationprogram, transmitting the transaction to the server, and converting thetransaction from the first language of the first end user application toa language running on the application server. Typically, as describedabove, the client will be a thin client or a Web browser, theapplication running on the client will be a Web browser application or athin client connectivity application, and the language of the clientapplication will be Java, C, C++, or a markup language, as HTML or aderivative of HTML, such as XML or Dynamic HTML or WML, or the like, andthe language running on the server is PL/I. The invention facilitatestransformers which convert the transaction from the first language ofthe end user application to a language running on the applicationserver. After conversion, the converted transaction is processed on theapplication server.

The application processes the request and then sends the response fromthe application server back to the end user application. Typically, asdescribed above, the application server will be running a PL/I basedapplication, and the client will be a thin client written in Java or Cor C++, or a Web browser, running a Web browser application or a thinclient connectivity application, in a markup language, as HTML or aderivative of HTML, such as XML or Dynamic HTML, or the like. Theinvention provides data transformers which convert the response from thelanguage or languages running on the application server or servers tothe first language of the first end user application.

The end user application and the application server have at least onedata transformer between them. In this way, the steps of (i) convertingthe request from the first language of the first end user application asa source language to the language running on an application server as atarget language, and (ii) converting the response from the languagerunning on the application server, as a subsequent source language, backto the first language of the first end user application, as a subsequenttarget language, each comprise the steps of invoking type descriptor andlanguage metamodels of respective source and target languages,populating the metamodels with each of the respective source and targetlanguages' data items and types, and converting the source language tothe target language.

The end user application is, frequently, a web browser or a thin client.When the end user application is a Web browser, the end user isconnected to the application server through a web server. According to afurther embodiment of the invention, the web server may comprise theconnector, or data transformer. The data transformer integrated with theWeb server may directly convert the request, transaction, or messagefrom a browser oriented form to an application server language or to anintermediate, business or commerce oriented markup language, such asXML.

The CAM metamodel used to construct the converter comprises aninvocation metamodel, an application domain interface metamodel, alanguage metamodel, and a type descriptor metamodel. Exemplaryinvocation metamodel includes information chosen from the groupconsisting of message control information, security data, transactionalsemantics, trace and debug information, pre-condition and post-conditionresources, and user data, etc. Exemplary application domain interfacemetamodel comprises information chosen from input parameter signatures,output parameter signatures, and return types. Application domaininterface metamodel uses one or more language metamodels, such as COBOLand PL/I metamodels.

The type descriptor metamodel defines physical realizations, storagemapping, data types, data structures, and realization constraints.

The method of the invention is applicable to situations where one of thesource or target languages is object oriented, and the other of thetarget or source languages is not object oriented. In this situation,the language metamodel and the type descriptor metamodel together mapencapsulated objects of the object oriented language into code and dataof the language that is not object oriented. Additionally, the languagemetamodel and the type descriptor metamodel maps object inheritances ofthe object oriented language into references and pointers in thelanguage that is not object oriented. The method of the invention isalso applicable to situations where different object oriented languagesare running on different platforms, and encapsulated objects of thesource language (code and data) are mapped into encapsulated objects ofthe target language. The method of the invention is also applicablewhere different procedural languages are running on different platformsor applications and commands and data of the source procedural languageare mapped into the target procedural language.

According to the method of the invention, there may be a plurality ofapplications for vertical (sequential, conditional, or dependent)processing, for horizontal (parallel in time) processing, or bothhorizontal and vertical processing. This is to support rich transactionsto and through multiple hierarchical levels and multiple parallelsequences of processing. This may be the case in business to businesstransactions drawing upon financial, manufacturing, scheduling, supply,and shipping databases and servers, and utilizing various commercialsecurity instruments.

A further aspect of the invention is a client-server processing systemhaving a client, a server, and at least one transformer between theclient and one or more servers,

A still further aspect of the invention is a processing systemconfigured and controlled to interact with a client application. In thisaspect of the invention, the system comprises, a server, and at leastone transformer between the server and the client application, where theclient has an end user application, and is controlled and configured toinitiate a request with the server in a first language with a firstapplication program and to transmit the request through a transformer tothe server or servers. The server processes the request in a secondsoftware application, using a second language, and returns a response tothe client through a transformer.

A further aspect of the invention is a groupware system having aplurality of e-mail enabled end user applications, such as e-mail, wordprocessing, spreadsheet, simple database management (such as LotusApproach or Microsoft Access), graphics and graphics editing, audio andaudio editing, and computer-telephony integration (“CTI”), along withclient level content database client services and content replicationclient services. Groupware integrates these e-mail enabled applicationsthrough one or more transformers and application program interfaces withtransport services, directory services, and storage services, includingcontent servers and replication servers. The groupware system isconfigured and controlled to communicate among disparate end userapplications, among disparate servers, and between disparate servers andend user applications. The groupware system comprises at least onetransformer between a server and an end user application. The end userapplication is controlled and configured to participate with a server ina first language of a first application program and the server isconfigured and controlled to participate with the client in a secondlanguage of a second program.

The transformer is configured and controlled to receive a request fromthe end user application, and convert the request from the firstlanguage of the first end user application to a language running on theserver. The server is configured and controlled to receive the convertedrequest from the transformer and process the request in a secondlanguage with a second application program residing on the server, andto thereafter transmit a response through a transformer back to the enduser application.

A still further embodiment of the invention is the provision of richtransaction processing. Rich transactions are nested transactions thatspan to, through, and/or across multiple servers. The spanning acrossnested servers may be horizontal, that is parallel dependenttransactions, or vertical, that is, serial dependent transactions. Richtransactions may be long lived, on-going transactions, or complexbusiness-to-business transactions, especially those with multipledependencies or contingencies, volume and prompt payment discounts, latedelivery and late payment penalties, and with financial processing, suchas electronic letters of credit, electronic bills of lading, electronicpayment guarantees, electronic payment, escrow, security interests inthe goods, and the like. In a rich transaction environment, sometransaction servers may be positioned as clients with respect to othertransactions for certain sub transactions making up the richtransaction.

A still further embodiment of the invention is a tool, that is, asoftware developer's kit, characterized in that the program product is astorage medium (as a tape, floppy disks, a CD-ROM, or a hard drive orhard drives on one of more computers) having invocation metamodels,application domain interface metamodels, and language metamodels, andcomputer instructions for building a metamodel repository of source andtarget language metamodels. The program product also contains computerinstructions for building connector stubs from the metamodels. Theprogram product further carries computer instructions to build atransformer.

While the invention has been described in summary form as having asingle level of connectors, it is, of course, to be understood that suchconnectors may be present at various levels in the processing hierarchy,for example between Web Clients and Web servers, between web servers andapplication servers, between application servers and database servers,and between application servers or database servers or both and variousspecialized repositories.

It is also to be understood, that while the invention has beensummarized in terms of individual clients and individual servers, theremay be multiple clients, multiple servers, and applications thatfunction as both clients and servers, as exemplified by groupwareapplications, and there might be multiple parallel lines and/or multiplehierarchical levels of application servers, data servers, and databases,as in systems for rich transactions.

THE FIGURES

Various elements of the invention are illustrated in the FIGURESappended hereto.

FIG. 1 illustrates a system with multiple application components,including a Netscape Internet Explorer browser, Net.Commerce on a SunSolaris server, Oracle and DB2 on a database server, SAP running on AIX,a CICS 390 server, an IMS 390 server, DB2 and DL/I on a S/390 platform,a Windows 200 client, and Baan running on an HP Unix server.

FIG. 2 illustrates the roles of message sets, SQL stored procedures,legacy applications, and programming languages as inputs to the metadatarepository of the Common Application Metamodel to facilitate enterpriseapplication integration at run time.

FIG. 3 illustrates that the Common Application Metamodel of theinvention consists of three kinds of metamodels, i.e., an invocationmetamodel, an application-domain interface metamodel, and a languagemetamodel. For any given application-domain metamodel it may use one ormany language metamodels, and there could be zero or many invocationmetamodels.

FIG. 4 illustrates an IMS OTMA metamodel, with an OTMA InvocationMetamodel, an IMS Transaction Message Metamodel application interface,which could use a COBOL Metamodel, a C Metamodel, or other languagemetamodels.

FIG. 5 illustrates how a tool can be used to generate an XML documentdescribing application program interface. First, an object model, i.e.,a CAM metamodel, is created to capture interface definitions about anapplication server. Then a tool reads and parses the source definitionsof an application program and generates an XML document by retrievingthe object model's information from a repository.

FIG. 6 illustrates a development phase scenario where a CommonApplication Metamodel Rose file, e.g., a COBOL metamodel, a PL/Imetamodel, an MFS metamodel, a BMS model, or the like is read into atoolkit, to generate a DTD and XML schema and Java code for a Rosemodel. A source file of an application, as a COBOL source file, a PL/Isource file, an MFS source file, a BMS source file, or the like, is readinto an importer. The importer parses the source code and generates, asoutput, an XMI instance file, i.e., XML documents, by reading in theJava code of the Rose model of the application source files.

FIG. 7 illustrates a metamodel for application interfaces, which enablesintegration of application components into an event based messagingmodel, including flow models. The flow and messaging middle invokesapplications through the application interface. These interfaces areaccess points to the applications through which all input and output isconnected to the middleware. The interfaces are described in terms ofthe Application Interface Metamodels. Transformation processingaccording to he metamodel could take place in source/clientapplications, target applications, or a gateway.

FIG. 8 illustrates the application of the Common Application Metamodelduring execution time. As shown, the CAM model facilitates connectivitybetween a back-end IMS application and a Web file (e.g., SOAP complaintXML documents). This is accomplished by using information captured inthe model to perform data transformations from one platform to anotherin a mixed language environment shown.

FIG. 9 illustrates TDLang base classes, where the Type Descriptormetamodel is used as a recipe or template for runtime datatransformation, with the language specific metamodel for overall datastructures and field names, and without duplicating the aggregationassociations present in the language model.

FIG. 10 illustrates an MOF class instance at the M2 level as a TypeDescriptor Metamodel.

FIG. 11 illustrates the association between a TDLangElement of theTDLang Metamodel with a Platform Compiler Type of the Type DescriptorMetamodel.

FIG. 12 illustrates various enumeration types for the Type DescriptorMetamodel, e.g., sign coding, length encoding, floating type, accessor,packed decimal sign, and bitModelPad.

FIG. 13 illustrates a PL/I language metamodel, which is usable byapplication programs to define data structures which represent connectorinterfaces. This metamodel is an MOF class instance at the M2 level.

FIG. 14 illustrates the associations between the PL/I metamodel with theTDLang base classes which are the TDLangClassifier, theTDLanguageComposedType, and the TDLanguageElement for the PL/IMetamodel.

FIG. 15 illustrates enumerations of Mode Values, Base Values,LengthTypes, and StringTypeValues for the PL/I Metamodel.

FIG. 16 illustrates a simplified network configuration for a “rich”transaction where, for example, an order is entered at a terminal, andis passed to and through a Web server to a manufacturer's applicationserver. The manufacturer's application server searches through it's owndatabase server, as well as its vendors' dissimilar and incompatibledatabase servers and databases, transparently connected by theconnectors described herein, querying for statuses, prices, and deliverydates, of components, and placing orders for needed components tosatisfy the order.

FIG. 17 illustrates a group ware session spread across multiple groupware applications running on multiple, disparate platforms, andconnected using the common application metamodel described herein.

FIG. 18 illustrates a commercial transaction where real goods areshipped from a seller to a buyer, and various forms of electronicpayment and secured electronic payment are used by the buyer to pay theseller, with banks and financial institutions connected using the commonapplication metamodel described herein.

DETAILED DESCRIPTION OF THE INVENTION

Definitions. As used herein the following terms have the indicatedmeanings. “Handshaking” is the exchange of information between twoapplications and the resulting agreement about which languages,capabilities, and protocols to use that precedes each connection.

An “application program interface” (API) is a passive specific methodprescribed by a computer operating system or by another applicationprogram by which a programmer writing an application program can makerequests of the operating system or another application. Exemplary isSAX (Simple API for XML), an connector that allows a programmer tointerpret a Web file that uses the Extensible Markup Language, that is,a Web file that describes a collection of data. SAX is an event-driveninterface. The programmer specifies an event that may happen and, if itdoes, SAX gets control and handles the situation. SAX works directlywith an XML parser.

A “connector” as used herein is a dynamic, run-time, interface betweenplatforms that stores the functions and parameters of the targetplatform or program, and binds with the target platform program in realtime.

A “stub” is a small program routine that provides static interfaces toservers. Precompiled stubs define how clients invoke correspondingservices on the server. The stub substitutes for a longer program on theserver, and acts as a local call or a local proxy for the server object.The stub accepts the request and then forwards it (through anotherprogram) to the remote procedure. When that procedure has completed itsservice, it returns the results or other status to the stub which passesit back to the program that made the request. Server services aredefined in the stub using an Interface Definition Language (“IDL”). Theclient has an IDL stub for each server interface that it accesses andincludes code to perform marshaling. Server stubs provide staticinterfaces to each service exported by the server.

“CICS” (Customer Information Control System) is the online transactionprocessing program from IBM that, together with the Common BusinessOriented Language programming language, is a set of tools for buildingcustomer transaction applications in the world of large enterprisemainframe computing. Using the programming interface provided by CICS towrite to customer and other records (orders, inventory figures, customerdata, and so forth) in a CICS, a programmer can write programs thatcommunicate with online users and read from a database (usually referredto as “data sets”) using CICS facilities rather than IBM's accessmethods directly. CICS ensures that transactions are completed and, ifnot, it can undo partly completed transactions so that the integrity ofdata records is maintained. CICS products are provided for OS/390, UNIX,and Intel PC operating systems. CICS also allows end users to use IBM'sTransaction Server to handle e-business transactions from Internet usersand forward these to a mainframe server that accesses an existing CICSorder and inventory database.

“IMS” (Information Management System) is the system from IBM that,together with IBM's Enterprise Systems Architecture (IMS/ESA) provides atransaction manager and a hierarchical database server.

“MQ” is the MQSeries IBM software family whose components are used totie together other software applications so that they can work together.This type of application is often known as business integration softwareor middleware. Functionally, MQSeries provides a communication mechanismbetween applications on different platforms, an integrator whichcentralizes and applies business operations rules, and a workflowmanager which enables the capture, visualization, and automation ofbusiness processes. MQSeries connects different computer systems, atdiverse geographical locations, using dissimilar IT infrastructures, sothat a seamless operation can be run. IBM's MQSeries suppliescommunications between applications, and between users and a set ofapplications on dissimilar systems. Additionally, MQSeries' messagingscheme requires the application that receives a message to confirmreceipt. If no confirmation materializes, the message is resent by theMQSeries.

“Rose” is an object-oriented Unified Modeling Language (UML) softwaredesign tool intended for visual modeling and component construction ofenterprise-level software applications. It enables a software designerto visually create (model) the framework for an application by blockingout classes with actors (stick figures), use case elements (ovals),objects (rectangles) and messages/relationships (arrows) in a sequencediagram using drag-and-drop symbols. Rose documents the diagram as it isbeing constructed and then generates code in the designer's choice ofC++, Visual Basic, Java, Oracle8, Corba or Data Definition Language.

Common Application Metamodel Overview. The Common Application Metamodel(CAM) brings interconnectivity to the environment illustrated in FIG. 1.FIG. 1 illustrates a typical system 101 with multiple applicationcomponents, including a Netscape Internet Explorer browser 103,Net.Commerce 105 on a Sun Solaris server 107, Oracle 109 and DB2 111 ona database server 113, SAP 115 running on AIX 117, a CICS 390 server119, an IMS 390 server 121, DB2 123 and DL/I 125 on a S/390 platform127, a Windows 2000 client 129, and Baan 131 running on an HP Unixserver 133. The Common Application Metamodel (CAM) is metadatainterchange method, tool, and system for marshaling and applyinginformation needed for accessing enterprise applications, such as inFIG. 1, in a source language and converting them to a target language.CAM consists of language metamodels and application domain interfacemetamodels, as shown in FIG. 2, which illustrates the roles of messagesets 203, SQL stored procedures 205, legacy applications 207, andprogramming languages 209 as inputs to the metadata repository 211 ofthe Common Application Metamodel to facilitate enterprise applicationintegration 221.

Exemplary metamodels include C, C++, Java, COBOL, PL/I, HL Assembler,IMS transaction messages, IMS MFS, CICS BMS, and MQSeries messagesmodels, as shown in FIG. 3, which illustrates the Common ApplicationMetamodel of the invention, with an invocation metamodel 301, anapplication-domain interface metamodel 303, and a language metamodel305.

FIG. 4 illustrates an IMS OTMA application interface metamodel 411, withan OTMA Invocation Metamodel 421, an IMS Transaction Message Metamodel423, a COBOL Metamodel 425, and a C Metamodel 427.

FIG. 5 illustrates the flow of information from an existing application501, through an interface 503 to an object model containing applicationinterface metadata. This application interface metamodel is stored inthe metadata repository 505, and, at an appropriate time, retrieved fromthe metadata repository 505, combined with a source program 507 in ageneration tool 509, and used to generate a target file 511, as an XMLfile, i.e., an XMI instance file. CAM is highly reusable and independentof any particular tool or middleware.

Development Stage. With CAM, tooling can now easily provide solutions toaccess enterprise applications, e.g. IMS applications. By parsing eachsource file and generating XML documents based on the CAM model, COBOLcopybook, PL/I copybook, MFS Source, BMS Source, etc., tools can provideconnector solutions to IMS, and CICS, etc.

In this regard, FIG. 6 illustrates a development phase scenario where aCommon Application Metamodel Rose file 601, e.g., a COBOL metamodel, aPL/I metamodel, an MFS metamodel, a BMS model, or the like is read intoa toolkit 603, to generate a DTD and schema for a Rose model and Javacode for a Rose model 605. A source file of an application 607, as aCOBOL source file, a PL/I source file, an MFS source file, a BMS sourcefile, or the like, and the Java code for the Rose model 609 are readinto an Importer 611. The importer parses the source code and provides,as output, an XMI instance file 613, i.e., XML documents, of theapplication source files.

FIG. 7 shows a CAM metamodel for application interfaces. This Figuredepicts a runtime connector 701 with invocation and transformationcapabilities, interfacing with an existing application program 703through an interface 705 containing the existing application program'sinterface definition, in accordance with the application interfacemetamodel 707. The Application Interface metadata is stored in ametadata repository 709.

The flow and messaging middleware 713 invokes applications 703 throughthe application interfaces 705. These interfaces 705 are the accesspoints to the applications 703 through which all input and output isconnected to the middleware 713. The interfaces 705 are described interms of the Application Interface Metamodel. Transformation processingaccording to the metamodel could take place in source/clientapplications, target applications, or a gateway.

Because CAM also provides physical representation of data types andstorage mapping to support data transformation in an enterpriseapplication integration environment, it enables Web services forenterprise applications. At development time CAM captures informationthat facilitates:

a). connector and/or connector-builder tools,

b). data driven impact analysis for application productivity and qualityassurance, and

c). viewing of programming language data declarations by developers.

The CAM metamodel files are inputs to toolkits used to generate DTDfiles, XML schemas, and Java classes which represent the CAM model.Importers parse each source file (e.g. COBOL or PL/I copybook, MFSsource, and BMS, etc.), and then generate XML documents (i.e. XMLinstance files) based on Java classes generated by the XMI/MOF2 toolkit.

Run Time. At run time CAM provides information which facilitatestransformation in an enterprise application integration environmentwhere it provides data type mapping between mixed languages, facilitatesdata translations from one language and platform domain into another.

FIG. 8 illustrates the application of the Common Application Metamodelduring run time. As shown, SOAP compliant XML documents 803 are receivedin, for example, IBM WebSphere middleware, 805, which contains anIMSConnector for Java 807, and is in contact with an XML Repository 809,containing the XMI instance files for the CAM model. The IBM WebSpheremiddleware sends the transformed file to the IMS system 811, whichcontains an instance of IMS Connect 813 and the IMS transactionalapplication program 815. CAM facilitates connectivity between theback-end IMS application 815 and the Web file (e.g., SOAP compliant XMLdocuments) 803. The CAM accomplishes this by using CAM model information(from repository 809) to perform data transformations from one platformto another in the mixed language environment shown.

Type Descriptor Metamodel. One important feature provided by CAM is theType Descriptor metamodel. The Type Descriptor metamodel defines thephysical realization, storage mapping, and the constraints on therealization (such as justification). This metamodel provides a physicalrepresentation of individual fields of a given data structure. Whensupporting data transformation in an enterprise application integrationenvironment, the model provides data type mapping between mixedlanguages. It also facilitates data translations from one language andplatform domain into another. The metamodel is used for runtime datatransformation (or marshaling) with a language-specific metamodel foroverall data structures and field names.

1. Common Application Metamodel for Application Interfaces

The interconnection of disparate and dissimilar applications running ondifferent software platforms, as shown in FIG. 1, with differentoperating systems, physical platforms, and physical realizations isaccomplished through connectors that incorporate the interconnectionmetadata. Connectors are a central part of the application framework fore-business. The end user demand is to connect to anything interesting asquickly, and as easily, as possible.

A connector is required to match the interface requirements of theadapter and the legacy application. It is also required to map betweenthe two interfaces. Standardized metamodels for application interfacespresented herein allow reuse of information in multiple connector tools.These standardized metamodels not only reduce work to create aconnector, but also reduce work needed to develop connector buildertools.

The connectors built using the common application metamodel of ourinvention provide interoperability with existing applications. Theconnectors support leveraging and reuse of data and business logic heldwithin existing application systems. The job of a connector is toconnect from one application system server “interface” to another.Therefore, an application-domain interface metamodel describessignatures for input and output parameters and return types for a givenapplication system domain (e.g. IMS, MQSeries); it is not for aparticular IMS or MQSeries application program. The metamodel containsboth syntactic and semantic interface metadata.

1. a. End-to-End Connector Usage Using Common Application Metamodel

The Common Application Metamodel (CAM) consists of meta-definitions ofmessage signatures, independent of any particular tool or middleware.Different connector builder tools can use this information to ensure the“handshaking” between these application programs, across differenttools, languages, and middleware. For example, if you have to invoke aMQSeries application, you would need to build a MQ message using datafrom a GUI tool and deliver it using the MQ API. Similarly, when youreceive a message from the MQSeries application, you would need to getthe buffer from MQSeries, parse it and then put it into a GUI tool datastructure. These functions can be designed and implemented efficientlyby a connector builder tool using CAM as standardized metamodels forapplication interfaces.

CAM can be populated from many sources, including copy books, togenerate HTML forms and JavaServer Page (JSP) for gathering inputs andreturning outputs. An example of a connector as depicted in the previousfigure is that the flow and message middleware makes a function call toan enterprise application by calling the connector which then calls theenterprise application API. The connector does language and data typemappings, for example, to translate between XML documents and COBOLinput and output data structures based on CAM. Connectors and CAMprovide the end-to-end integration between the middleware and theenterprise applications.

Using IMS as an example. Let's say that you must pass an account numberto an IMS transaction application program from your desktop to withdraw$50.00. With CAM and a connector builder tool, you will first generatean input HTML form and an output JSP; and develop a middleware codenecessary to support the request. The desktop application fills therequest data structure (i.e. an input HTML form) with values and callsthe middleware. The middleware service code will take the data from theGUI tool, build an IMS Connect XML-formatted message, and deliver themessage to the IMS gateway (i.e. IMS Connect) via TCP/IP. IMS Connecttranslates between the XML documents and the IMS message data structuresin COBOL using the metadata definitions captured in CAM. It then in turnsends the IMS message data structures to IMS via Open TransactionManager Access (OTMA). The IMS COBOL application program runs, andreturns the output message back to the middleware service code via IMSConnect. The middleware service code gets the message and populates theoutput JSP page (i.e. previously generated GUI tool reply datastructures) with the reply data. The transaction output data will thenbe presented to the user.

2. Common Application Metamodel

CAM is used to describe information needed to easily integrateapplications developed in common programming models with other systems.The CAM metamodel can be used for both synchronous and asynchronousinvocations.

2. a. Common Application Metamodel

The common application metamodel depicted as follows consists of aninvocation metamodel and an application-domain interface metamodel whichuses language metamodels. For any given application-domain interfacemetamodel, it may use one or many language metamodels, but, there couldbe zero or more invocation metamodels.

The common connector metamodel is illustrated in FIG. 3. It has anInvocation Metamodel 301, an Application-Domain Interface Metamodel 303,and a Language Metamodel 305.

2. a. i. Invocation Metamodel

The invocation metamodel 301 consists of one or more of the followingpossible metadata elements. However, for a particular invocation, itcould include only one or many of the following metadata elements.

Message-control information. This includes message control information,such as the message connection name, message type, sequence numbers (ifany), and various flags and indicators for response,commit-confirmation, and processing options by which a client or servercan control message processing to be synchronous or asynchronous, etc.

The connection name can be used by the application system server toassociate all input and output with a particular client. The messagetype specifies that the message is a response message; or that commit iscomplete. It can also indicate server output data to the client, orclient input data to the server.

Security data—This includes authentication mechanism, and security data,e.g. digital certificates, identity, user name and password, etc. It mayalso include authorization information to indicate whether the data canbe authorized via a role based or ACL (access control list) basedauthorization.

Transactional semantics—This will carry transaction information, e.g.local vs. global transaction; two-phase commit vs. one-phase commit, andtransaction context, etc.

Trace and debug—Trace and debugging information are specified as part ofthe metamodel.

Precondition and post-condition resource—This describes applicationstate precondition and post-condition relationships.

User data—This includes any special information required by the client.It can contain any data.

2. a. ii. Application-Domain Interface Metamodel

The application-domain interface metamodel 303, as discussed earlier,describes signatures for input and output parameters and return typesfor application system domains.

2. a, iii. Language Metamodel

The language metamodel 305, e.g. COBOL metamodel, is used by enterpriseapplication programs to define data structures (semantics) whichrepresent connector interfaces. It is important to connector tools toshow a connector developer the source language, the target language, andthe mapping between the two. The CAM language metamodel also includesthe declaration text in the model which is not editable (i.e. read-onlymodel). Because the connector/adapter developer would probably prefer tosee the entire COBOL data declaration, including comments and any otherdocumentation that would help him/her understand the business roleplayed by each field in the declaration.

The language metamodel is also to support data driven impact analysisfor application productivity and quality assurance. (But, it is not theintention of the CAM to support reproduction of copybooks.)

The language metamodels describing connector data are listed as follows:

-   -   *C    -   *C++    -   *COBOL    -   *PL/I        2. a. iv. Type Descriptor Metamodel

The Type Descriptor metamodel is language neutral and defines thephysical realization, storage mapping and the constraints on therealization such as justification. This metamodel provides physicalrepresentation of individual fields of a given data structure. The typedescriptor metamodel is to support data transformation in an enterpriseapplication integration environment to provide data types mappingbetween mix languages. It also facilitates data translations from onelanguage and platform domain into another. This metamodel will be usedas a recipe for runtime data transformation (or marshaling) withlanguage specific metamodel for overall data structures and fieldsnames.

3. An Example of Common Connector Metamodel

IMS OTMA (Open Transaction Manager Access) is a transaction-based,connectionless client/server protocol within an OS/390 sysplexenvironment. An IMS OTMA transaction message consists of an OTMA prefix,plus message segments for input and output requests. Both input andoutput message segments contain llzz (i.e. length of the segment andreserved field), and application data. Only the very first input messagesegment will contain transaction code in front of the application data.IMS transaction application programs can be written in a variety oflanguages, e.g. COBOL, PL/I, C, and Java, etc. Therefore, theapplication data can be in any one of these languages.

As shown in FIG. 4, an IMS OTMA connector metamodel 401 is composed ofan invocation metamodel 403 and an IMS transaction message metamodel405, as well as a COBOL metamodel 407 and a C metamodel 409. As depictedin FIG. 4, the invocation metamodel 401 is the OTMA prefix, and the IMStransaction message metamodel 405 is the application-domain interfacemetamodel for the IMS application system which uses language metamodels.Metamodels for COBOL 407 and C 409 are shown.

4. Type Descriptor Metamodel

The type descriptor metamodel presents a language and platformindependent way of describing implementation types, including arrays andstructured types. This information is needed for marshaling and forconnectors, which have to transform data from one language and platformdomain into another. Inspections of the type model for differentlanguages can determine the conformance possibilities for the languagetypes. For example, a long type in Java is often identical to a binarytype (computational-5) in COBOL, and if so, the types may beinter-converted without side effect. On the other hand, an alphanumerictype in COBOL is fixed in size and if mapped to a Java type, loses thisproperty. When converted back from Java to COBOL, the COBOL truncationrules may not apply, resulting in computation anomalies. In addition,tools that mix languages in a server environment (e.g., Java and COBOLin CICS and IMS) should find it useful as a way to determine howfaithfully one language can represent the types of another.

Therefore, an instance of the type descriptor metamodel describes thephysical representation of a specific data type for a particularplatform and compiler.

4. a. TDLang Metamodel

The TDLang metamodel serves as base classes to CAM language metamodelsby providing a layer of abstraction between the Type Descriptormetamodel and any CAM language metamodel. All TDLang classes areabstract and common to all the CAM language metamodels. All associationsbetween TDLang classes are marked as “volatile,” “transient,” or“derived” to reflect that the association is derived from the languagemetamodel. The TDLang model does not provide any function on its own,but it is the type target for the association from the Type Descriptormetamodel to the language metamodels.

FIG. 9 illustrates the structure of the TDLang Metamodel, with theTDLangClassifier 501, the TDLangComposedType 503 and the TDLangElement505.

With the TDLang base classes, the Type Descriptor metamodel can be usedas a recipe for runtime data transformation (or marshaling) with thelanguage-specific metamodel for overall data structures and field names,without duplicating the aggregation associations present in the languagemodel.

4. b. Type Descriptor Metamodel

This metamodel is a MOF Class instance at the M2 level. FIG. 10 showsthe relationships within the type descriptor Metamodel, including thePlatformCompilerType 601, the InstanceTDBase 603, the ArrayTD 605, theAggregateInstanceTD 607, the Simple InstanceTD 609, and the InstanceType611. The InstanceType 611 comprises definitions of the StringTD 613, theAddressTD 615, the NumberTD 617, and the FloatTD 619. FIG. 11illustrates a higher level view of the TDLanguageElement and thePlatformCompilerType 601. FIG. 12 illustrates enumerations of signCoding801, lengthEncoding 803, floatType 805, accessor 807, packedDecimalSign809, and bitModePad 811.

4. C. Type Descriptor and Language Models

The Type Descriptor model is attached to the CAM Language model by anavigable association between TDLangElement and InstanceTDBase.TDLangElement is the base language model type used to represent adeclared data item, i.e., an instance of a type. InstanceTDBase is thebase Type Descriptor model type used to represent theimplementation-specific instance of this same declared data item.InstanceTDBase is abstract; only one of its subtypes may beinstantiated.

It is possible that a data item declared in a programming language mayhave different implementations. These differences are induced byhardware platform, system platform, and compiler differences. Thispossibility is modeled by the PlatformCompilerType model type. Theassociation between TDLangElement and PlatformCompilerType is many toone, and the association between PlatformCompilerType and InstanceTDBaseis one to one. To navigate from the language model, it is necessary toknow what PlatformCompilerType is to be assumed. It is possible that animplementation, upon importing a model instance, will wish to removefrom the model the PlatformCompilerType instances that are not ofinterest.

The association between TDLangElement and InstanceTDBase is modeled inthis manner to allow for extending the model to include an associationbetween PlatformCompilerType and a new type that more fully describesthe hardware platform, the system platform, and the compiler.

Data element instances may be defined as repeating groups or arrays.This is modeled as a one to many association between InstanceTDBase andthe ArrayTD model type. There would be one ArrayTD instance in thisassociation for each dimension, subscript, or independent index of thedata element. These instances hold information about the bounds andaccessing computations.

The association is ordered in the same order as the correspondingassociation in the language model, and reflects the syntactic orderingof the indices as defined by the programming language. The rationale forthis choice is the resulting equivalence of navigation and processingalgorithms between the language model and the Type Descriptor model.Another choice, perhaps more advantageous to marshaling engines, wouldbe to have the ordering of the indices from the smallest stride to thelargest. This allows a marshaling engine to process the array in itsnatural storage order, assuming it is laid out in the usual contiguousfashion. A marshaling engine can compute this order by re-sorting theassociation targets according to the stride formulas if desired.

Array information may be a complex property of the data element or ofits type, and various languages and programming practices seem to fallon either side. The typedef facility of C and C++ allows the definitionof some array types from typedefs, but only where the array definitionsare applied to the topmost elements of typedef aggregates. For example,consider the following typedef:

typedef struct {   int A;   struct {     int C;     char D;     struct {      int F;       int G;     } E;   } B; } X;

This typedef can be used to create a new typedef for a fixed size array,e.g.typedef X Q[10];

But it is not possible to create a new typedef from X that makes any ofthe subcomponents of X, e.g., D or E, into an array. This example andmany others point out the unclear status of array definitions in typedlanguages.

An InstanceTDBase type has two concrete subtypes, SimpleInstanceTD andAggregateInstanceTD. SimpleInstanceTD models data elements withoutsubcomponents, while AggregateInstanceTD models data elements withsubcomponents. To find the subcomponents of an AggregateInstanceTD, onemust navigate back to the corresponding data element declaration in theCAM language model. There, the association between an aggregate type andits subcomponents may be navigated, leading to a set of subcomponentdata elements, each of which has one or more corresponding instances inthe Type Descriptor model. This introduces some model navigationcomplexity, but avoids duplicating the aggregation hierarchy in both thelanguage and the Type Descriptor models. The additional processingcomplexity of traversal is not great, and considerable simplification isobtained in algorithms that would modify the model to add, delete orrearrange subcomponents in an aggregation.

A SimpleInstanceTD model type is also associated one to one with aBaseTD model type. The BaseTD model type is specialized to holdimplementation information that is common for all data elements of thesame language type. The information that describes a 32-bit signedbinary integer on a specific hardware/software platform is thusinstantiated only once in a given model instantiation, no matter howmany data elements may be declared with this type.

One may contemplate an association between TDLangClassifier and BaseTDmatching the association between TDLangElement and InstanceTDBase.However, this is problematic in that constructions that the languageregards as simple types (e.g., strings) may not map directly to simplehardware/software types. Rather than introduce more mechanisms into theType Descriptor model to describe string implementations, aspecialization of BaseTD is utilized which describes the common stringimplementations. Various attributes in the TypeDescriptor model aresuffixed with the string “formula.” These attributes contain informationthat may in some cases be impossible to compute without access to datacreated only at run-time. An example is the current upper bound of avariable-sized array or the offset to an element that follows anotherelement whose size is only known at run-time. Such information could beincluded as values in a model instance, but this would require a modelinstance for each run-time instance, and would mean that the model couldonly be constructed at run-time, requiring the model definition toinclude factories and other apparatus to create model instances atrun-time. A model that can be constructed from platform and compilerknowledge is much more useful, and the formulas provide a way to defineconcrete values when the run-time information is available. Theseformulas may be interpreted by marshaling engines, or they may be usedto generate marshaling code, which is loaded and executed by themarshaling engine on demand.

4. d. Formulas

As used in connection with formulas, “field” refers to a component of alanguage data structure described by the Type Descriptor model, while“attribute” denotes part of the model, and has a value representing a“property” of the field. Thus the value of a field means a run-timevalue in a particular instance of a language data structure, whereas thevalue of an attribute is part of the description of a field in alanguage data structure, applies to all instances of the data structure,and is determined when the data structure is modeled.

For most attributes in an instance of the Type Descriptor model, thevalue of the attribute is known when the instance is built, because theproperties of the fields being described, such as size and offset withinthe data structure, are invariant. But if a field in a data structure isdefined using the COBOL OCCURS DEPENDING ON construct or the PL/I Referconstruct, then some properties of the field (and properties of otherfields that depend on that field's value) cannot be determined when themodel instance is built.

Properties that can be defined using these language constructs arestring lengths and array bounds. A property that could indirectly dependon these language constructs is the offset of a field within astructure, if the field follows a variable-size field.

In order to handle these language constructs, properties of a field thatcould depend on these constructs (and thus the values of thecorresponding attributes), are defined with strings that specify aformula that can be evaluated when the model is used.

However, if a property of a field is known when the model instance isbuilt, then the attribute formula simply specifies an integer value. Forexample, if a string has length 17, then the formula for its length is“17”.

The formulas mentioned above are limited to the following:

-   -   Unsigned integers    -   The following arithmetic integer functions    -    neg(x):=−x //prefix negate    -    add(x,y):=x+y //infix add    -    sub(x,y):=x−y //infix subtract    -    mpy(x,y):=x*y //infix multiply    -    div(x,y):=x/y //infix divide    -    max(x,y):=max(x,y)    -    min(x,y):=min(x,y)    -    mod(x,y)=x mod y

The mod function is defined as mod(x,y) =r where r is the smallestnon-negative integer such that x−r is evenly divisible by y. So mod(7,4)is 3, but mod(−7,4) is 1. If y is a power of 2, then mod(x,y) is equalto the bitwise-and of x and y−1.

*The val function

The val function returns the value of a field described by the model.The val function takes one or more arguments, and the first argumentrefers to the level-1 data structure containing the field, and must beeither:

-   -   the name of a level-1 data structure in the language model    -   the integer 1, indicating the level-1 parent of the        variable-size field. In this case, the variable-size field and        the field that specifies its size are in the same data        structure, and so have a common level-1 parent.

The subsequent arguments are integers that the specify the ordinalnumber within its substructure of the (sub)field that should bedereferenced.

By default, COBOL data fields within a structure are not aligned ontype-specific boundaries in storage. For example, the “natural”alignment for a four-byte integer is a full-word storage boundary. Suchalignment can be specified by using the SYNCHRONIZED clause on thedeclaration. Otherwise, data fields start immediately after the end ofthe preceding field in the structure. Since COBOL does not have bitdata, fields always start on a whole byte boundary.

For PL/I, the situation is more complicated. Alignment is controlled bythe Aligned and Unaligned declaration attributes. By contrast withCOBOL, most types of data, notably binary or floating-point numbers, arealigned on their natural boundaries by default.

4. d. i) Formula examples PL/I

1. Given the following structure

dcl /* offset */ 1 c unaligned /* “0” */ ,2 c1 /* “0” */ ,3 c2 fixedbin(31) /* “0” */ ,3 c3 fixed bin(31) /* “4” */ ,2 c4 /* “8” */ ,3 c5fixed bin(31) /* “0” */ ,3 c6 fixed bin(31) /* “4” */ ,3 c7 fixedbin(31) /* “8” */ ,2 c8 fixed bin(31) /* “20” */ ,2 c9 char( *refer(c7))/* “24” */ ,2 c10 char(6) /* “add(24,val(1,2,3))” */ ,2 c11 char(4) /*“add(add(24,val(1,2,3)),6)” */;

The offset of c3 would be given by the simple formula “4”, but theoffset of c10 would be given by the formula:“add(24,val(1,2,3))”

The first argument in the above val function is 1, which indicates thecurrent structure, c. The subsequent arguments are 2 and 3, indicatingthat the third element, c7, of the second level-2 field, c4, is thefield to be dereferenced.

The offset of C11 is equal to the offset of c10 plus the length of c10and would be given by the following formula:“add(add(24,val(1,2,3)),6)”

PL/I structure mapping is not top-down, and this can be illustrated byexamining the mapping of the following structure:

dcl /* offset */ 1 a based, /* “0” */ 2 b, /* “0” */ 3 b1 fixed bin(15),/* “0” */ 3 b2 fixed bin(15), /* “2” */ 3 b3 fixed bin(31), /* “4” */ 2c, /* “add(8,mod(neg(val(1,1,1)),4))” */ 3 c1 char( n refer(b1)), /* “0”*/ 3 c2 fixed bin(31); /* “val(1,1,1)” */

The value of b1 is given by val(1,1,1), and in order to put c2 on a4-byte boundary, PL/I puts any needed padding before c (yes, not betweenc1 and c2), and hence the offset of c would be given by the followingformula:“add(8,mod(neg(val(1,1,1)),4))”

So if b1 contains the value 3, then this formula becomesadd(8,mod(neg(3),4)), which evaluates to 9. I.e., there is one byte ofpadding between the structure b and the structure c.

The model also uses these formulas to specify the bounds and strides inan array, where the stride is defined as the distance between twosuccessive elements in an array.

For example, in the following structure, the second dimension of a.e hasa stride specified by the formula “4”, and the first dimension by theformula “20”:

dcl  1 a,      /* offset = “0”   */  2 b(4) fixed bin(31),  /* offset =“0”   */ /* lbound(1) = “1”   */ /* hbound(1) = “4”   */ /* stride(1) =“4”   */ 2 c(4) fixed bin(31),  /* offset “ 16”   */ /* lbound(1) = “1”  */ /* hbound(1) = “4”   */ /* stride(1) = “4”   */ 2 d(4) char(7)varying,   /* offset = “32”   */ /* lbound(1) = “1”   */ /* hbound(1) =“4”   */ /* stride(1) = “9”   */ 2 e(4,5) fixed bin(31);  /* offset =“68”   */ /* lbound(1) = “1”   */ /* hbound(1) = “4”   */ /* stride(1) =“20”   */ /* lbound(2) = “1”   */ /* hbound(2) = “5”   */ /* stride(1) =“4”   */

This means that to locate the element a.e(m,n), one would take theaddress of a.e and add to it(m−1)*20+(n−1)*4.

If the example were changed slightly to:

dcl 1 a(4),   /* offset = “0”    */ /* lbound(1) = “1”    */ /*hbound(1) = “4”   */ /* stride(1) = “40”   */ 2 b fixed bin(31),  /*offset = “0”    */ 2 c fixed bin(31),  /* offset = “4”    */ 2 d char(7)varying, /* offset = “8”    */ 2 e(5) fixed bin(31); /* offset = “20”   */ /* lbound(1) = “1”   */ /* hbound(1) = “5”   */ /* stride(1) = “4”  */then there is padding between d and e, but the user of the typedescriptor can be blissfully unaware and simply use the stride andoffset formulas to locate any given array element.

The stride for a is “40”, the stride for e is “4”, and the offset for eis “20”. This means that to locate the element a(m).e(n), one would takethe address of a and add to it (m−1)*40+20+(n−1)*4.

Finally, if the example were changed again to:

dcl 1 a(4),  /* offset = “0”     */ /* lbound(1) = “1”   */ /* hbound(1)= “4”    */ /* stride(1) = “40”    */ 2 b fixed bin(31) ,  /* offset =“0”    */ 2 c(8) bit(4),    /* offset = “4”    */ /* lbound(1) = “1”   */ /* hbound(1) = “8”   */ /* stride(1) = “4”    */ 2 d char(7) varying,/* offset = “8”    */ 2 e(5) fixed bin(31) ; /* offset = “20”   */ /*lbound(1) = “1”   */ /* hbound(1) = “5”    */ /* stride(1) = “4”   */then the computations for a.e are the same as above, but thecomputations for a.c become interesting.

The stride for a is still “40”, the stride for c is “4” (but this “4” isa count of bits, not bytes), and the byte offset for c is “4”. To locatethe element a(m).c(n), one needs both a byte address and a bit offset.For the byte address, one would take the address of a and add to it(m−1)*40+4+((n−1)*4)/8. The bit offset of a(m).c(n) would be given bymod((n−1)*4,8).

4. e. Type Descriptor Specification

4. e. i. TDLang Metamodel Specification

TDLang Classes—General Overview. TDLang classes serve as a layer ofabstraction between any CAM language model and the TypeDescriptor model.

Since any CAM language model can plug into the TDLang model, the TypeDescriptor model only needs to understand how to interface with TDLangin order to access any CAM language model.

The TDLang model does not provide any function on its own and thereforeonly makes sense when it is attached to a language model. TDLang iscommon to all the CAM language models and is the type target for theassociation from TypeDescriptors to the language models.

Note all TDLang classes are abstract and they serve as the base classesto the language metamodels.

TDLangClassifier. TDLangClassifier is the parent class of alllanguage-specific Classifier classes and TDLangComposedType. TheTDLangSharedType association is derived from the language's“+sharedType” association from Element to Classifer class. Theassociation should be marked “volatile,” “transient,” or “derived” toreflect that the association is derived from the language model. TheTDLangClassifier is derived from TDLangModelElement

TDLangElement. TDLangElement is the parent class of alllanguage-specific Element classes. The tdLangTypedElement association isderived from the language's “+typedElement” association from Classiferto Element class. The association should be marked “volatile”,“transient”, and “derived” to reflect that the association is derivedfrom the language model.

The tdLangElement association is derived from the language's “+element”association from Classifer to Element class. The association should bemarked “volatile,” “transient,” or “derived” to reflect that theassociation is derived from the language model.

TDLangComposedType. The TDLangComposedType is the parent class of alllanguage-specific ComposedTypes. The TDLangGroup association is derivedfrom the language's “+group” association from Element to ComposedTypeclass. The association should be marked “volatile,” “transient,” or“derived” to reflect that the association is derived from the languagemodel. The TDLangComposedType is derived from TDLangClassifier.

4. e. ii. Type Descriptor Metamodel Specification

The Type Descriptor package defines a model for describing the physicalimplementation of a data item type. This model is language neutral andcan be used to describe the types of many languages. Inspections of thetype model for different languages can determine the conformancepossibilities for the language types. For example, a long type in Javais often identical to a binary type in COBOL, and if so, the types maybe interconverted without side effect. On the other hand, analphanumeric type in COBOL is fixed in size and if mapped to a Javatype, will lose this property. When converted back from Java to COBOL,the COBOL truncation rules may not apply, resulting in computationanomalies.

AggregateInstanceTD. For each instance of an aggregate, there is aninstance of this class. To find the children of this aggregate, one mustnavigate the associations back to language Classifier then downcast tolanguage Composed Type and follow the association to its children.

-   -   Derived from InstanceTDBase    -   Public Attributes:        -   union: boolean=false    -   Distinguishes whether the aggregation is inclusive (e.g. a        structure) or exclusive (e.g. a union).    -   If union=true, storage might be overlaid and as a result the        interpretation of the content may be uncertain.        ArrayTD. ArrayTD holds information for array types.    -   Public Attributes:        -   arraryAlign: int    -   Alignment requirements in addressible units for each element in        the array. strideFormula: string    -   A formula that can be used to calculate the displacement address        of any element in the array, given an index.    -   strideInBit: boolean        -   True indicates strideFormula value in bits        -   False indicates strideFormula value in bytes    -   upperBoundFormula: String    -   Declared as a String for instances when this value is referenced        by a variable.    -   This attribute supplies the upperbound value of a variable size        array    -   Upperbound is required when traversing back up the entire        structure.    -   lowerBoundFormula: String    -   Declared as a String for instances when this value is referenced        by a variable.    -   This attribute supplies the lowerbound value of a variable size        array.        InstanceTDBase. InstanceTD has instances for each declared        variable and structure element.

To find the parent of any instance (if it has one) one must navigate theassociations back to TDLangElement, follow the association toTDLangClassifier to locate the parent, then follow the associations backinto the TypeDescriptor model.

-   -   Public Attributes:    -   offsetFormula: string    -   A formula for calculating the offset to the start of this        instance.    -   This attribute is String because this field may not always be an        integer value. For example, (value(n)+4) could be a possible        value.    -   NOTE: The offset value is calculated from the top-most parent.        (e.g., for a binary tree A→B, A→C, B→D, B→E. The offset to D is        calculated from A to D, not B to D)    -   contentSizeFormula: string    -   Formula for calculating the current size of the contents    -   allocSizeFormula: string    -   Formula for calculating the allocated size of the instance    -   formulaInBit: boolean    -   True indicates offsetFormula, contentSizeFormula, and        allocSizeFormula values are in bits    -   False indicates offsetFormula, contentSizeFormula, and        allocSizeFormula values are in bytes    -   defaultEncoding: String    -   Physical encoding—how many bits used to encode code points, how        are the code points mapped onto bit patterns    -   Contains info on how string content is encoded: EBCDIC, ASCII,        UNICODE, UTF-8, UTF-16, codepage numbers, etc . . .    -   accessor: enumeration    -   Specifies access-rights for this element.    -   defaultBigEndian: boolean    -   True if this element is Big Endian format.    -   floatType: enumeration    -   Specifies this element's float type.        PlatformCompilerType. A specific data type for a particular        platform and compiler.        NOTE: There needs to be some way to identify the platform and        compiler. This class can be specialized or have an attribute, or        be simplified by putting an attribute on InstanceTDBase.

-   Public Attributes:    -   platformCompilerType: String    -   This attribute specifies the type of compiler used to create the        data in the language model. Usage of this string is as follows:    -   “Vendor name, language, OS, hardware platform” (e.g., “IBM,        COBOL, OS390, 390” or “IBM, PLI, WinNT, Intel”)        SimpleInstanceTD. An instance of a Simple type in the language        model.        Derived from InstanceTDBase

-   NumberTD    -   All numbers representations.    -   Currently includes Integers and Packed Decimals    -   Note required fields for these types of Numbers:    -   *Integer*    -   Base=2    -   MSBU=0 or 1    -   Signed/Unsigned    -   Size (in bytes) =1,2,4,8 (16)    -   *Packed Decimal*    -   Base=10    -   MSBU=0    -   Signed    -   Width=1-63    -   *Float*    -   Base=2(IEEE), 16(Hex)    -   MSBU=0 or 1    -   Signed    -   Size (in bytes)=4,8,16    -   Encoding Details . . .    -   Derived from BaseTD    -   Public Attributes:    -   base: int    -   The base representation of this number. 2=binary, 10=decimal,        16=hex,    -   . . .    -   baseWidth: int    -   Number of bits used to represent base:    -   e.g. binary=1, decimal=8, packed=4    -   baseInAddr: int    -   Number of baseWidth units in addressable storage units—e.g.        decimal=1, packed=2, binary=8 where the addressable unit is a        byte. If the addressable unit was a 32 bit word, decimal would        be 4, packed would be 8, and binary would be 32.    -   baseUnits: int    -   Number of base units in the number. This times the base width        must be less than or equal to the width times the addrUnit.    -   For example, a 24 bit address right aligned in a 32 bit word        would have base=1, basewidth=24, baseInAddr=8, width=4.    -   signcoding: enumeration    -   A set of enumerations—2's complement, 1's complement, and sign        magnitude for binary; zone signs for decimal, packed signs for        packed decimal, and unsigned binary, unsigned decimal.    -   checkValidity: boolean    -   True if language model is required for picture string support        packedDecimalSign: enumeration    -   Used to determine the code point of the sign in COBOL decimal        numbers, where the sign is combined with the leading or trailing        numeric digit.

-   FloatTD    -   Floating points    -   Derived from BaseTD    -   Public Attributes:    -   floatType: enumeration    -   Specifies this element's float type.

-   I StringTD    -   Alphanumeric type    -   Derived from BaseTD    -   Public Attributes:    -   encoding: String    -   Physical encoding—how many bits used to encode code points, how        are the code points mapped onto bit patterns    -   Contains info on how string content is encoded: EBCDIC, ASCII,    -   UNICODE, UTF-8, UTF-16, codepage numbers, etc . . .    -   lengthEncoding: enumeration    -   Possible values for lengthEncoding:        -   Fixed length (where total length equals declared string            length)        -   Length prefixed (where total length equals declared string            length plus length of header bytes; usually 1, 2, or 4            bytes)        -   Null terminated (known as varyingZ strings in PL/I) (where a            null symbol is added to the end of string; so the maximum            length could be up to declared string length plus one byte            to represent null character)    -   maxLengthFormula: String    -   Formula specifying the maximum length of this string.    -   checkValidity: boolean    -   True if language model is required for picture string support    -   textType: String=Implicit    -   Value is ‘Implicit’ or ‘Visual’    -   orientation: StringTD=LTR    -   Value is ‘LTR’, ‘RTL’, ‘Contextual LTR’, or ‘Contextual RTL’    -   where LTR=Left to Right    -   and RTL=Right to Left    -   Symmetric: boolean=true    -   True if symmetric swapping is allowed    -   numeralShapes: String=Nominal    -   Value is ‘Nominal’, ‘National’, or ‘Contextual’    -   textShape: String=Nominal    -   Value is ‘Nominal’, ‘Shaped’, ‘Initial’, ‘Middle’, ‘Final’, or        ‘Isolated’

-   AddressTD

-   Type to represent pointers/addresses

-   Rationale for this class:    Addresses should be considered separate from NumberTD class because    some languages on certain machines (e.g., IBM 400) represent    addresses with additional information, such as permission type    (which is not represented in NumberTD class) Derived from BaseTD

-   Public Attributes:

-   permission: String

-   Specifies the permission for this address. Used primarily for AS/400    systems.

-   bitModePad: enumeration

-   Specifies the number of bits for this address. Used to calculate    padding.

-   BaseTD    -   The base class of typeDescriptor.

The BaseTD model type is specialized to hold implementation informationwhich is common for all data elements of the same language type. Theinformation which describes a 32 bit signed binary integer on a specifichardware/software platform is thus instantiated only once in a givenmodel instantiation, no matter how many data elements may be declaredwith this type.

-   -   Public Attributes:    -   addrUnit: enumeration    -   Number of bits in storage addressable unit        -   bit/byte/word/dword    -   width: int    -   Number of addressable storage units in the described type. This        can be 1, 8, 16, 32 bits.    -   alignment: int    -   Required alignment of type in address space—e.g. word aligned 32        bit integer would have alignment of 4    -   nickname: int    -   Name of the base element. This should uniquely identify an        instance of a simple type to allow logic based on name rather        than logic based on combinations of attributes. E.g.        “S390Binary31_(—)0” for a 32 bit S/390 unsealed binary integer    -   bigEndian: boolean    -   True if this element is Big Endian format.

-   Stereotypes

-   bitModePad    -   Public Attributes:    -   16 bit:    -   24 bit:    -   31 bit:    -   32 bit:    -   64 bit:    -   128 bit:

-   signcoding    -   Note that this model does not include the following COBOL        usages:        -   I POINTER        -   PROCEDURE-POINTER        -   OBJECT REFERENCE    -   Public Attributes:    -   twosComplement:    -   onesComplement:    -   signMagnitude:    -   zoneSigns:    -   packedSigns:    -   unsignedBinary:    -   unsignedDecimal:    -   lengthEncoding    -   Public Attributes:    -   fixedLength:    -   lengthPrefixed:    -   nullTerminated:

-   floatType    -   Public Attributes:    -   Unspecified:    -   IEEEextendedIntel:    -   For IEEE extended floats running on Intel Platform    -   EEEextendedAIX:    -   For IEEE extended floats running on AIX Platform    -   EEEextended0S390:    -   For IEEE extended floats running on OS/390 Platform    -   IEEEextendedAS400:    -   For IEEE extended floats running on AS400 Platform    -   IEEEnonextended:    -   For IEEE non-extended floats    -   IBM390Hex:    -   For Hexadecimal floats running on IBM OS/390    -   IBM400Hex:    -   For Hexadecimal floats running on IBM AS400

-   accessor    -   Public Attributes:    -   ReadOnly:    -   WriteOnly:    -   ReadWrite    -   NoAccess

-   packedDecimalSign    -   Public Attributes:    -   MVS:    -   MVSCustom:    -   NT/OS2/AIX:        5. Language Metamodels        5. b. PL/I Metamodel

The PLI language metamodel is used by enterprise application programs todefine data structures (semantics) which represent connector interfaces.This metamodel is a MOF Class instance at the M2 level. FIG. 13illustrates a PL/I language metamodel, which is usable by applicationprograms to define data structures which represent connector interfaces.This metamodel is an MOF class instance at the M2 level. FIG. 14illustrates the TDLangClassifier, the TDLanguageComposedType, and theTDLanguageElement for the PL/I Metamodel. FIG. 15 illustratesenumerations of Mode Values, Base Values, LengthTypes, andStringTypeValues for the PL/I Metamodel.

5. b. i. PL/I Metamodel Specification

-   PLI    -   The PLI language metamodel is used by enterprise application        programs to define data structures (semantics) which represent        connector interfaces,    -   This language model for PL/I attempts to describe PL/I declares        that have the storage class of either PARAMETER, STATIC or        BASED. CONTROLLED, AUTOMATIC and DEFINED are not supported.    -   In the PL/I languages, extents( that is string lengths, area        sizes and array bounds) may, in general, be declared as        constants, as expressions to be evaluated at run-time, as        asterisks, or as defined via the REFER option; however, none of        these choices are valid for all storage classes.    -   Based variables whose extents are not constant and not defined        via the REFER option are excluded from this model, as are        parameters whose extents are specified via asterisks.    -   The INITIAL attribute (which is not valid for parameters in any        case) will be ignored by the model.-   PLISimpleType    -   PLISimpleType is an abstract class that contains attributes        shared by all simple types in the PLI language.    -   Derived from PLIClassifier-   PLIElement    -   * A PLIDeclaration represents every data definition in the PLI        program.    -   * For example:    -   DCL 1 Employee,        -   2 Name,            -   3 Last char(29),            -   3 First char(29),        -   2 Deparment char(5);    -   where Eemployee, Name, Last, First, and Department are all PLI        Elements.        -   ntation.    -   Derived from TDLangElement    -   Public Attributes:    -   level: String-   PLIComposedType    -   PLIComposedType is a collection of member elements that can be        structure, unions, or elementary variables and arrays.        PLIComposedType has a single aggregation to include all the        elements that are a part of this composition.    -   A structure is a data aggregate whose elements need not have        identical attributes. Like an array, the entire tructure is        given a name that can be used to refer to the entire aggregate        of data. Unlike an array, however, each element of a structure        also has a name.    -   A structure has different levels. At the first level is the        structure name called a major structure. At a deeper level are        the names of substructures called minor structures. At the        deepest are the element names called elementary names. An        elementary name in a structure can represent an array, in which        case it is not an element variable, but an array variable.    -   The organization of a structure is specified in a DECLARE        statement through the use of level numbers preceding the        associated names; level numbers must be integers. A major        structure name is declared with the level number 1. Minor        structures and elementary names are declared with level numbers        greater than 1.    -   The description of a major structure name is terminated by one        of the following:        -   The declaration of another item with a level number 1        -   The declaration of another item with no level number        -   A semicolon terminating the DECLARE statement    -   A delimiter (usually a blank) must separate the level number and        its associated name. For example, the items of a payroll can be        declared as follows:        -   DECLARE 1 PAYROLL,            -   2 NAME,                -   3 LAST CHAR(20),                -   3 FIRST CHAR(15),            -   2 HOURS,                -   3 REGULAR FIXED DEC(5,2),                -   3 OVERTIME FIXED DEC(5,2),            -   2 RATE,                -   3 REGULAR FIXED DEC(3,2),                -   3 OVERTIME FIXED DEC(3,2);    -   Indentation is only for readability. The statement could be        written in a continuous string as DECLARE 1 PAYROLL, 2 NAME, 3        LAST CHAR(20), etc.    -   PAYROLL is declared as a major structure containing the minor        structures NAME, HOURS, and RATE. Each minor structure contains        two elementary names. You can refer to the entire structure by        the name PAYROLL, or to portions of the structure by the minor        structure names. You can refer to an element by referring to an        elementary name.    -   The level numbers you choose for successively deeper levels need        not be consecutive. A minor structure at level n contains all        the names with level numbers greater than n that lie between        that minor structure name and the next name with a level number        less than or equal to n. PAYROLL might have been declared as        follows:        -   DECLARE 1 PAYROLL,            -   4 NAME,            -   5 LAST CHAR(20),            -   5 FIRST CHAR(15),        -   2 HOURS,            -   6 REGULAR FIXED DEC(5,2),            -   5 OVERTIME FIXED DEC(5,2),        -   2 RATE,            -   3 REGULAR FIXED DEC(3,2),            -   3 OVERTIME FIXED DEC(3,2);    -    This declaration results in exactly the same structuring as the        previous declaration.    -   Derived from PLIClassifier, TDLangComposedType    -   Public Attributes:    -   Union: Boolean-   PLIElementInitialValue    -   The INITIAL attribute specifies an initial value or values        assigned to a variable at the time storage is allocated for it.        Only one initial value can be specified for an element variable.        More than one can be specified for an array variable. A        structure or union variable can be initialized only by separate        initialization of its elementary names, whether they are element        or array variables. The INITIAL attribute cannot be given to        constants, defined data, noncontrol led parameters, and        non-LIMITED static entry variables.    -   The INITIAL attribute has three forms.        -   1. The first form, INITIAL, specifies an initial constant,            expression, or function reference, for which the value is            assigned to a variable when storage is allocated to it.        -   2. The second form, INITIAL CALL, specifies (with the CALL            option) that a procedure is invoked to perform            initialization. The variable is initialized by assignment            during the execution of the called routine. (The routine is            not invoked as a function that returns a value to the point            of invocation.)        -   3. The third form, INITIAL TO, specifies that the pointer            (or array of pointers) is initialized with the address of            the character string specified in the INITIAL LIST. The            string also has the attributes indicated by the TO keyword.    -   Derived from TDLangElement    -   Public Attributes:    -   initialValue: String    -   ValueType: PLIInitalValueType-   PLIClassifier    -    PLI type    -   Derived from TDLangClassifier-   PLISourceText    -    This class contains the entire source code (including comments)        and its associated line number.    -   Public Attributes:    -   source: String    -   fileName: String-   PLIComputationalType    -    Computational types represent values that are used in        computionals to produce a desired result. Arthmetic and string        data consitute computional data    -   Derived from PLISimpleType-   PLIArithmeticType    -    Aritmetic data are rational numbers    -   Derived from PLIComputationalType    -   Public Attributes:    -   mode: ModeValues-   PLIStringType    -    a string is a sequence of contiguous characters, bit,        cidechars, or graphics that are treated a a single data item    -   Derived from PLIComputationalType-   PLIIntegerType    -    Declared as Fixed Bin. with precision and scale factors. The        precision is the total number of digits and the scale is the        number of digits to the right of the binary point.    -    Example    -    DCL bindata BINARY FIXED (7,3)    -    could be used to present the number 1011.111B that is 7 data        bits, 3 of which is to the right of the binary point.    -   Derived from PLIArithmeticType    -   Public Attributes:    -   precision: Integer    -   scale: Integer    -   Signed: Boolean    -   BigEndian: Boolean=true-   PLIFloatType    -    has precision=2A decimal floating-point constant is a mantissa        followed by an exponent. The mantissa is a decimal fixed-point        constant. The exponent is the letter E followed by an optionally        signed integer, which specifies a power of ten. Decimal        floating-point constants have a precision (p), where p is the        number of digits of the mantissa.    -    Examples are:        -   15E−23 has precision=2        -   15E23 has precision=2)        -   4E−3 has precision=1        -   1.96E+07 has precision=3        -   438E0 has precision=3        -   3141593E−6 has precision=7        -   0.003141593E3 has precision=9    -   The last two examples represent the same value (although with        different precisions).    -   The data attributes for declaring decimal floating-point        variables are DECIMAL and FLOAT. For example:        -   DECLARE LIGHT_YEARS DECIMAL FLOAT(5);        -   LIGHT_YEARS represents decimal floating-point data items            with at least 5 decimal digits.    -   A binary floating-point constant is a mantissa followed by an        exponent and the letter B. The mantissa is a binary fixed-point        constant. The exponent is the letter E, followed by an        optionally signed decimal integer, which specifies a power of        two. Binary floating-point constants have a precision (p) where        p is the number of binary digits of the mantissa.    -   Examples are:        -   101101E5B has precision=6        -   101.101E2B has precision=6        -   11101E28B has precision=5        -   11.01E+42B has precision=4    -   The data attributes for declaring binary floating-point        variables are BINARY and FLOAT. For example:        -   DECLARE S BINARY FLOAT (16);        -   S represents binary floating-point data items with a            precision of 16 binary digits.    -   The default precision is (21). The exponent cannot exceed three        decimal digits. Binary floating-point data is stored as        normalized hexadecimal floating-point. If the declared precision        is less than or equal to (21), short floating-point form is        used. If the declared precision is greater than (21) and less        than or equal to (53), long floating-point form is used. If the        declared precision is greater than (53), extended floating-point        form is used.    -   Derived from PLIArithmeticType    -   Public Attributes:    -   base: BaseValues    -   precision: Integer    -   IEEE: Boolean=false    -   BigEndian: Boolean=true-   PLIPackedType    -   The data attributes for declaring decimal fixed-point variables        are DECIMAL and FIXED. For example:        -   declare A fixed decimal (5,4);    -   specifies that A represents decimal fixed-point data of 5        digits, 4 of which are to the right of the decimal point.    -   These two examples:        -   declare B fixed (7,0) decimal;        -   declare B fixed decimal(7);    -   both specify that B represents integers of 7 digits.    -   This example        -   declare C fixed (7,−2) decimal;    -   specifies that C has a scaling factor of −2. This means that C        holds 7 digits that range from −9999999*100 to 9999999*100, in        increments of 100.    -   This example        -   declare D decimal fixed real(3,2);        -   specifies that D represents fixed-point data of 3 digits, 2            of which are fractional.    -   Derived from PLIArithmeticType    -   Public Attributes:    -   precision: Integer    -   scale: Integer-   PLIPictureType    -   Numeric picture data is numeric data that is held in character        form Derived from PLIArithmeticType    -   Public Attributes:    -   pictureString: String-   PLICodedStringType    -   Derived from PLIStringType    -   Public Attributes:    -   type: StringTypeValues    -   varying: LengthType-   PLIPictureStringType    -   A character picture specification describes a fixed-length        character data item, with the additional facility of indicating        that any position in the data item can only contain characters        from certain subsets of the complete set of available        characters.    -   A character picture specification is recognized by the        occurrence of an A or X picture specification character. The        only valid characters in a character picture specification are        X, A, and 9. Each of these specifies the presence of one        character position in the character value, which can contain the        following:    -   X Any character of the 256 possible bit combinations represented        by the 8-bit byte.    -   A Any alphabetic character, #, @, $, or blank.    -   9 Any digit, or blank. (Note that the 9 picture specification        character in numeric character specifications is different in        that the corresponding character can only be a digit).    -   When a character value is assigned, or transferred, to a        pictured character data item, the particular character in each        position is checked for validity, as specified by the        corresponding picture specification character, and the        CONVERSION condition is raised for an invalid character.        (However, if you change the value either via record-oriented        transmission or using an alias, there is no checking).    -   For example:        -   DECLARE PART# PICTURE ‘AAA99X’;        -   PUT EDIT (PART#) (P‘AAA99X’);    -   The following values are valid for PART#:        -   ‘ABC12M’        -   ‘bbb09/’        -   ‘XYZb13’    -   The following values are not valid for PART# (the invalid        characters are underscored):        -   ‘AB123M’        -   ‘ABC1/2’        -   ‘Mb#A5;’    -   Derived from PLIStringType    -   Public Attributes:    -   pictureString: String-   PLINonComputationalType    -   Represents values that are used to control execution of your        program. It consists of the following data types—area, entry,        label, file, format, pointer, and offset.    -   Derived from PLISimpleType-   PLILabelType    -   A label is a label constant or the value of a label variable.    -   A label constant is a name written as the label prefix of a        statement (other than PROCEDURE, ENTRY, PACKAGE, or FORMAT) so        that during execution, program-control can be transferred to        that statement through a reference to it. In the following line        of code, for example, Abcde is a label constant.        Abcde: Miles=Speed*Hours;    -   The labelled statement can be executed either by normal        sequential execution of instructions or by using the GO TO        statement to transfer control to it from some other point in the        program.    -   A label variable can have another label variable or a label        constant assigned to it. When such an assignment is made, the        environment of the source label is assigned to the target. If        you declare a static array of labels to have initial values, the        array is treated as nonassignable.    -   A label variable used in a GO TO statement must have as its        value a label constant that is used in a block that is active at        the time the GO TO is executed. Consider the following example:        -   declare Lbl_x label;        -   Lbl_a: statement;        -   Lbl_b: statement;        -   Lbl_x=Lbl_a;        -   go to Lbl_x;    -   Lbl_a and Lbl_b are label constants, and Lbl_x is a label        variable. By assigning Lbl_a to Lbl_x, the statement GO TO Lbl_x        transfers control to the Lbl_a statement. Elsewhere, the program        can contain a statement assigning Lbl_b to Lbl_x. Then, any        reference to Lbl_x would be the same as a reference to Lbl_b.    -   This value of Lbl_x is retained until another value is assigned        to it.    -   If a label variable has an invalid value, detection of such an        error is not guaranteed. In the following example, transfer is        made to a particular element of the array Z based on the value        of I.        -   go to Z(I);        -   Z(1): if X=Y then return;        -   Z(2): A=A+B+C*D;        -   Z(3): A=A+10;    -   If Z(2) is omitted, GO TO Z(I) when I=2 raises the ERROR        condition. GO    -   TO Z(I) when I<LBOUND(Z) or I>HBOUND(Z) causes unpredictable        results if the SUBSCRIPTRANGE condition is disabled.    -   Derived from PLINonComputationalType-   PLIFormatType    -   The remote (or R) format item specifies that the format list in        a FORMAT statement is to be used.    -   The R format item and the specified FORMAT statement must be        internal to the same block, and they must be in the same        invocation of that block.    -   A remote FORMAT statement cannot contain an R format item that        references itself as a label-reference, nor can it reference        another remote FORMAT statement that leads to the referencing of        the original FORMAT statement.    -   Conditions enabled for the GET or PUT statement must also be        enabled for the remote FORMAT statement(s) that are referred to.    -   If the GET or PUT statement is the single statement of an        ON-unit, that statement is a block, and it cannot contain a        remote format item.    -   For example:        -   DECLARE SWITCH LABEL;        -   GET FILE(IN) LIST(CODE);        -   IF CODE=1            -   THEN SWITCH=L1;            -   ELSE SWITCH=L2;        -   GET FILE(IN) EDIT (W,X,Y,Z)            -   (R(SWITCH));        -   L1: FORMAT (4 F(8,3));        -   L2: FORMAT (4 E(12,6));    -   SWITCH has been declared to be a label variable; the second GET        statement can be made to operate with either of the two FORMAT        statements.    -   Data format items describe the character or graphic        representation of a single data item. They are:    -   A—Character    -   B—Bit    -   C—Complex    -   E—Floating point    -   F—Fixed point    -   G—Graphic    -   P—Picture    -   The remote format item specifies a label reference whose value        is the label constant of a FORMAT statement located elsewhere.        The FORMAT statement contains the remotely situated format        items. The label reference item is: R.    -   The first data format item is associated with the first data        list item, the second data format item with the second data list        item, and so on. If a format list contains fewer data format        items than there are items in the associated data list, the        format list is reused. If there are excessive format items, they        are ignored.    -   Suppose a format list contains five data format items and its        associated data list specifies ten items to be transmitted. The        sixth item in the data list is associated with the first data        format item, and so forth. Suppose a format list contains ten        data format items and its associated data list specifies only        five items. The sixth through the tenth format items are        ignored.    -   Example:        GET EDIT (NAME, DATA, SALARY)(A(N), X(2), A(6), F(6,2));    -   This example specifies that the first N characters in the stream        are treated as a character string and assigned to NAME. The next        2 characters are skipped. The next 6 are assigned to DATA in        character format. The next 6 characters are considered an        optionally signed decimal fixed-point constant and assigned to        SALARY.    -   Derived from PLINonComputationalType-   PLIEntryType    -   Entry data can be an entry constant or the value of an entry        variable.    -   An entry constant is a name written as a label prefix to a        PROCEDURE or ENTRY statement, or a name declared with the ENTRY        attribute and not the VARIABLE attribute, or the name of a        mathematical built-in function.    -   An entry constant can be assigned to an entry variable. For        example:        -   P: PROCEDURE;        -   DECLARE EV ENTRY VARIABLE,            -   (E1,E2) ENTRY;        -   EV=E1;        -   CALL EV;        -   EV=E2;        -   CALL EV;    -   P, E1, and E2 are entry constants. EV is an entry variable. The        first CALL statement invokes the entry point El. The second CALL        invokes the entry point E2.    -   The following example contains a subscripted entry reference:        -   DECLARE (A,B,C,D,E) ENTRY,        -   DECLARE F(5) ENTRY VARIABLE            -   INITIAL (A,B,C,D,E);        -   DO I=1 TO 5;        -   CALL F(I) (X,Y,Z);        -   END;    -   The five entries A, B, C, D, and E are each invoked with the        parameters X, Y, and Z.    -   When an entry constant which is an entry point of an internal        procedure is assigned to an entry variable, the assigned value        remains valid only for as long as the block that the entry        constant was internal to remains active (and, for recursive        procedures, current).    -   ENTRYADDR built-in function and pseudovariable allows you to get        or set the address of the entry point of a PROCEDURE or an    -   ENTRY in an entry variable. The address of the entry point is        the address of the first instruction that would be executed if        the entry were invoked. For example:        PTR1=ENTRYADDR(ENTRY_VBL);    -   obtains the address of the entry point, and        -   ENTRYADDR(ENTRY_VBL)=PTR2;    -   Derived from PLINonComputationalType    -   Public Attributes:    -   Limited: Boolean-   PLIAreaType    -   Area variables describe areas of storage that are reserved for        the allocation of based variables. This reserved storage can be        allocated to, and freed from, based variables by the ALLOCATE        and FREE statements. Area variables can have any storage class        and must be aligned.    -   When a based variable is allocated and an area is not specified,        the storage is obtained from wherever it is available.        Consequently, allocated based variables can be scattered widely        throughout main storage. This is not significant for internal        operations because items are readily accessed using the        pointers. However, if these allocations are transmitted to a        data set, the items have to be collected together. Items        allocated within an area variable are already collected and can        be transmitted or assigned as a unit while still retaining their        separate identities.    -   You might want to identify the locations of based variables        within an area variable relative to the start of the area        variable. Offset variables are provided for this purpose.    -   An area can be assigned or transmitted complete with its        contained allocations; thus, a set of based allocations can be        treated as one unit for assignment and input/output while each        allocation retains its individual identity.    -   The size of an area is adjustable in the same way as a string        length or an array bound and therefore it can be specified by an        expression or an asterisk (for a controlled area or parameter)        or by a REFER option (for a based area).    -   The area size for areas that have the storage classes AUTOMATIC        or CONTROLLED is given by an expression whose integer value        specifies the number of reserved bytes.    -   If an area has the BASED attribute, the area size must be an        integer unless the area is a member of a based structure and the        REFER option is used.    -   The size for areas of static storage class must be specified as        an integer.    -   Examples of AREA declarations are:    -   DECLARE AREA1 AREA(2000),        -   AREA2 AREA;    -   In addition to the declared size, an extra 16 bytes of control        information precedes the reserved size of an area. The 16 bytes        contain such details as the amount of storage in use.    -   The amount of reserved storage that is actually in use is known        as the extent of the area. When an area variable is allocated,        it is empty, that is, the area extent is zero. The maximum        extent is represented by the area size. Based variables can be        allocated and freed within an area at any time during execution,        thus varying the extent of an area.    -   When a based variable is freed, the storage it occupied is        available for other allocations. A chain of available storage        within an area is maintained; the head of the chain is held        within the 16 bytes of control information. Inevitably, as based        variables with different storage requirements are allocated and        freed, gaps occur in the area when allocations do not fit        available spaces. These gaps are included in the extent of the        area.    -   No operators, including comparison, can be applied to area        variables. Derived from PLINonComputationalType-   PLIPointerType    -   A pointer variable is declared contextually if it appears in the        declaration of a based variable, as a locator qualifier, in a        BASED attribute, or in the SET option of an ALLOCATE, LOCATE, or        READ statement. It can also be declared explicitly.    -   Derived from PLINonComputationalType-   PLIFileType    -   The FILE attribute specifies that the associated name is a file        constant or file variable.    -   The FILE attribute can be implied for a file constant by any of        the file description attributes. A name can be contextually        declared as a file constant through its appearance in the FILE        option of any input or output statement, or in an ON statement        for any input/output condition.    -   Derived from PLINonComputationalType-   PLIOffsetType    -   You might want to identify the locations of based variables        within an area variable relative to the start of the area        variable. Offset variables are provided for this purpose.    -   Derived from PLINonComputationalType    -   Public Attributes:    -   BigEndian: Boolean=true-   PLIAlias    -   An alias is a type name that can be used wherever an explicit        data type is allowed. Using the DEFINE ALIAS statement, you can        define an alias for a collection of data attributes. In this        way, you can assign meaningful names to data types and improve        the understandability of a program. By defining an alias, you        can also provide a shorter notation for a set of data        attributes, which can decrease typographical errors.    -   Example        -   define alias Name char(31) varying;        -   define alias Salary fixed dec(7); /* real by default */        -   define alias Zip char(5)/* nonvarying by default */    -   Derived from PLINamedType-   Attribute    -   The attributes that can be specified are any of the attributes        for variables that can be returned by a function (for example,        those attributes valid in the RETURNS option and attribute).        That is, you cannot specify an alias for an array or a        structured attribute list. However, you can specify an alias for        a type that is defined in a DEFINE ORDINAL, or DEFINE STRUCTURE        statement or in another DEFINE ALIAS statement. Also, as in the        RETURNS option and attribute, any string lengths or area sizes        must be restricted expressions.    -   Missing data attributes are supplied using PL/I defaults.    -   Public Attributes:    -   attribute: String-   PLIOrdinal    -   An ordinal is a named set of ordered values. Using the DEFINE        ORDINAL statement, you can define an ordinal and assign        meaningful names to be used to refer to that set. For example,        you can define an ordinal called “color”. The “color” ordinal        could include the members “red”, “yellow”, “blue”, etc. The        members of the “color” set can then be referred to by these        names instead of by their associated fixed binary value, making        code much more self-documenting. Furthermore, a variable        declared with the ordinal type can be assigned and compared only        with an ordinal of the same type, or with a member of that        ordinal type. This automatic checking provides for better        program reliability.    -   In the following example, Red has the value 0, Orange has the        value 1, etc. But Low has the value 2 and Medium has the value        3.    -   Example        -   define ordinal Color (Red, /* is 0, since VALUE is omitted            */        -   Orange,        -   Yellow,        -   Green,        -   Blue,        -   Indigo,        -   Violet);    -   define ordinal Intensity (Low value(2),        -   Medium,        -   High value(5));    -   Derived from PLINamedType    -   Public Attributes:    -   precision: int    -   isSigned: boolean-   OrdinalValue    -   OrdinalValue specifies the value of a particular member within        the set. If the VALUE attribute is omitted for the first member,        a value of zero is used. If the VALUE attribute is omitted for        any other member, the next greater integer value is used.    -   The value in the given (or assumed) VALUE attribute must be an        integer, can be signed, and must be strictly increasing. The        value in the given (or assumed) VALUE attributed may also be        specified as an XN constant.    -   Example    -   define ordinal Intesity (low vcalue(2), middle, high value (5));    -   will give low a value of 2, middle a value of 3, and high a        value of 5.    -   Public Attributes:    -   name: String    -   value: int-   PLIStructure    -   A structure is a collection of member elements that can be        structure, unions, or elementary variables and arrays.    -   Unions are a collection of member elements that overlay each        other, occupying the same storage. Unions can be used to declare        variant records that typically contain a common part, a selector        part, and a variant part    -   DEFINE STRUCTURE statement is used to specify a named structure        or union. Structures are stronly typed. That is only variables        declared as structures can be assigned to variables or        parameters declared as structures.    -   Derived from PLINamedType, PLIComposedType-   PLIHandleType    -   use HANDLE to declare a variable as a pointer to a structure        type.    -   Handle are strongly typed—they can be assigned to or compared        with handles for the same structure type    -   Derived from PLINonComputationalType    -   Public Attributes:    -   structure: tPLIStructure-   PLINamedType    -   PL/I allows you to define your own named types using the        built-in data types. These include user-defined types        (aliases,ordinals, structures, and unions), declarations of        variables with these types, handles, and type functions.    -   Derived from PLIClassifier-   PLIArray    -   An array is an n-dimensional collection of elements that have        identical attributes.    -   Examples    -   dcl List fixed decimal(3) dimension(8)    -   is a 1 dimensional array with 8 fixed-point decimal elements    -   dcl table (4,2) fixed dec (3)    -   is a 2 dimensional array of three fixed-point decimal elements        the 2 dimensions of table have lower bounds of 1 and upper        bounds of 4 for 1 dimension and lower bounds of 1 and upper        bounds of 2 for the other    -   The REFER option is used in the declaration of a based structure        to specify that, on allocation of the structure, the value of an        expression is assigned to a variable in the structure and        represents the length, bound, or size of another variable in the        structure. The syntax for a length, bound, or size with a REFER        option is:    -   expression REFER (variable)    -   The variable, known as the object of the REFER option, must be a        member of the declared structure. The REFER object must conform        to the following rules:    -   It must be REAL FIXED BINARY(p,0).    -   It must precede the first level-2 element that has the REFER        option or contains an element that has the REFER option.    -   It must not be locator-qualified or subscripted.    -   It must not be part of an array.    -   For example:    -   DECLARE 1 STR BASED(P),        -   2 X FIXED BINARY,        -   2 Y (L REFER (X)),        -   L FIXED BINARY INIT(1000);    -   This declaration specifies that the based structure STR consists        of an array Y and an element X. When STR is allocated, the upper        bound is set to the current value of L which is assigned to X.        For any other reference to Y, such as a READ statement that sets        P, the bound value is taken from X.    -   If both the REFER option and the INITIAL attribute are used for        the same member, initialization occurs after the object of the        REFER has been assigned its value.    -   Any number of REFER options can be used in the declaration of a        structure, provided that at least one of the following        restrictions is satisfied:    -   All objects of REFER options are declared at logical level two,        that is, not declared within a minor structure. For example:        -   DECLARE 1 STR BASED,            -   2 (M,N),            -   2 ARR(I REFER (M),                -   J REFER(N)),            -   2 X;    -   When this structure is allocated, the values assigned to I and J        set the bounds of the two-dimensional array ARR.    -   The structure is declared so that no padding between members of        the structure can occur. For example:        -   DECLARE 1 STR UNAL BASED (P),            -   2 B FIXED BINARY,            -   2 C,                -   3 D FLOAT DECIMAL,                -   3 E (I REFER (D))                -   CHAR(J REFER (B)),            -   2 G FIXED DECIMAL;    -   All items require only byte alignment because this structure has        the UNALIGNED attribute. Therefore, regardless of the values of        B and D (the REFER objects) no padding occurs. Note that D is        declared within a minor structure.    -   If the REFER option is used only once in a structure        declaration, the two preceding restrictions can be ignored        provided that:    -   For a string length or area size, the option is applied to the        last element of the structure.    -   For an array bound, the option is applied either to the last        element of the structure or to a minor structure that contains        the last element. The array bound must be the upper bound of the        leading dimension. For example:        -   DCL 1 STR BASED (P),            -   2 X FIXED BINARY,            -   2 Y,                -   3 Z FLOAT DECIMAL,                -   3 M FIXED DECIMAL,            -   2 D (L REFER (M)),                -   3 E (50),                -   3 F (20);    -   The leading dimension of an array can be inherited from a higher        level. If we had declared STR(4) in the above example, the        leading dimension would be inherited from STR(4) and so it would        not be possible to use the REFER option in D.    -   This declaration does not satisfy the two previous bulleted        restrictions. The REFER object M is declared within a minor        structure and padding occurs. However, this restriction is        satisfied because the REFER option is applied to a minor        structure that contains the last element.    -   The following example is also valid:        -   DCL 1 STR BASED(P),            -   2 X FIXED BINARY(31),            -   2 Y,                -   3 Z FLOAT DECIMAL,                -   3 M FIXED BINARY(31),                -   3 N FIXED BINARY(31),            -   2 D,                -   3 E(50),                -   3 F(L REFER (M))                -   CHAR(K REFER (N));    -   If the value of the object of a REFER option varies during the        program then:    -   The structure must not be freed until the object is restored to        the value it had when allocated.    -   The structure must not be written out while the object has a        value greater than the value it was allocated.    -   The structure can be written out when the object has a value        equal to or less than the value it had when allocated. The        number of elements, the string length, or area size actually        written is that indicated by the current value of the object.        For example:        -   DCL 1 REC BASED (P),            -   2 N,            -   2 A (M REFER(N)),        -   M INITIAL (100);        -   ALLOCATE REC;        -   N=86;        -   WRITE FILE (X) FROM (REC);    -   86 elements of REC are written. It would be an error to attempt        to free REC at this point, since N must be restored to the value        it had when allocated (that is, 100). If N is assigned a value        greater than 100, an error occurs when the WRITE statement is        encountered.    -   When the value of a refer object is changed, the next reference        to the structure causes remapping. For example:        -   DCL 1 A BASED(P),            -   2 B,            -   2 C (I REFER(B)),            -   2 D,        -   I INIT(10);        -   ALLOCATE A;        -   B=5;    -   The next reference to A after the assignment to B remaps the        structure to reduce the upper bound of C from 10 to 5, and to        allocate to D storage immediately following the new last element        of C. Although the structure is remapped, no data is        reassigned—the contents of the part of storage originally        occupied by the structure A are unchanged. If you do not        consider remapping, errors can occur. Consider the following        example, in which there are two REFER options in the one        structure:        -   DCL 1 A BASED (P),            -   2 B FIXED BINARY (15,0),            -   2 C CHAR (I1 REFER (B)),            -   2 D FIXED BINARY (15,0),            -   2 E CHAR (I2 REFER (D)),        -   (I1,I2) INIT (10);        -   ALLOCATE A;        -   B=5;    -   The mapping of A with B=10 and B=5, respectively, is as follows:    -    D now refers to data that was originally part of that assigned        to the character-string variable C. This data is interpreted        according to the attributes of D—that is, as a fixed-point        binary number—and the value obtained is the length of E. Hence,        the length of E is unpredictable.-   PLIFixedLengthString    -   Derived from PLICodedStringType    -   Public Attributes:    -   length: Integer-   PLIVariableLengthString    -   Derived from PLICodedStringType    -   Public Attributes:    -   lengthToAllocate: String-   PLIFixedLengthArea    -   Derived from PLIAreaType    -   Private Attributes:    -   length: Integer-   PLIVariableLengthArea    -   The size of an area is adjustable in the same way as a string        length or an array bound and therefore it can be specified by an        expression or an asterisk (for a controlled area or parameter)        or by a REFER option (for a based area).    -   Derived from PLIAreaType    -   Private Attributes:    -   lengthToAllocate: String-   PLIFixedBoundArray    -   Derived from PLIArray    -   Public: Attributes:    -   lbound: Integer    -   ubound: Integer-   PLIFixedLboundArray    -   Derived from PLIArray    -   Public Attributes:    -   Ibound: Integer    -   HboundtoAllocate: String-   PLIHboundArray    -   Derived from PLIArray    -   Public Attributes:    -   LboundtoAllocate: String    -   ubound: Integer-   PLIVariableBoundArray    -   Derived from PLIArray    -   Public Attributes:    -   LboundToAllocate: String    -   HboundToAllocate: String-   TOTALS:    -   1 Logical Packages    -   39 Classes-   LOGICAL PACKAGE STRUCTURE    -   Logical View        -   PLI        -   TDLang            6. Illustrative Applications of the Common Application            Metamodel and System

Various complex transaction, occurring across a plurality of individualplatforms require the seamlessness and transparency of the CommonApplication Metamodel. These transactions include “rich” transactions,high level group ware, and financial transactions.

FIG. 16 illustrates a simplified network configuration for a “rich”transaction where, for example, an order is entered at a terminal, andis passed to and through a Web server to a manufacturer's applicationserver. The manufacturer's application server searches through it's owndatabase server, as well as its vendors' dissimilar and incompatibledatabase servers and databases, transparently connected by theconnectors described herein, querying for statuses, prices, and deliverydates, of components, and placing orders for needed components tosatisfy the order.

Strictly for purposes of illustration and not limitation, a richtransaction is illustrated with the purchase of an automobile, fromconfiguring and ordering the new automobile through financing theautomobile, collecting the elements and components the new automobile,assembling the automobile, and delivering it to the customer. Inconfiguring the automobile, consider the inclusion of, e.g., a tractioncontrol module, which may require the inclusion of one sub-set ofengines, while precluding the inclusion of another sub-set of engines,for example, for technical or performance reasons. Similarly, theselection of one color may preclude the selection of certain upholsterycombinations, for example, for reasons of inventory or availability. Ofcourse, if you don't select an engine and a transmission, you don't havean automobile. Certain choices must be made. The problem is one of “Ifyou pick ‘X’, you must also pick ‘Y’ and ‘Z’, but if you pick ‘Y’, youcan not get ‘A’ or ‘B’, and you have already selected ‘A’.” That is,selection of one component or sub-system may remove some previouslyselected components or sub-systems from the system. After configuringthe car, frequently based on the availability of selected elements inthe supply pipeline, the order is sent to the manufacturer's server forfulfillment, including manufacturing scheduling. The manufacturer wouldquery the vendors in the supply chain, for example, a transmissionvendor, who would, in turn, query controller vendors, gear vendors,housing vendors, hydraulic conduit vendors, and the like. These vendorswould, in turn query their sub-vendors.

Using the connector method and system, the dealer and customer wouldconfigure and order the car at a terminal 3901. The configuration andorder entry would be sent to the manufacturer's server 3911. Themanufacturer's server queries the servers 3921, 3931, and 3441, (whereserver 3921 could be the server for the manufacturer's in housecomponents business and for its purchasing function) or its directvendors, who in turn query third sub-vendors, 3923, 3933, and 3933. Thequeries could be in the form of “fill in the blank” SQL queries, subjectto access authorizations. The sub-vendor servers, 3923, 3933, and 3443specialized views to the vendor's servers 3921, 3931, 3441, as clients,which in turn would present specialized views to the manufacturer'sserver 3911 as a client. The data returned to the manufacturer's server3911 could be optimized with optimization and production schedulingapplications, to present a serial number and delivery date to the buyerat the dealer's server.

A further application of the connectors of the present invention is inconnection with groupware, and especially linking “islands of groupware”together. “Groupware” is a broad term applied to technology that isdesigned to facilitate the work of groups. Groupware technology may beused to communicate, cooperate, coordinate, solve problems, compete, ornegotiate. A Groupware suite of applications is comprised of programsthat help people work together collectively, even if located remotelyfrom each other. Groupware services can include the sharing ofcalendars, collective writing, e-mail handling, shared database access,electronic meetings, video conferencing, and other activities.

FIG. 17 illustrates a group ware session spread across multiple groupware applications running on multiple, disparate platforms, andconnected by the connectors described herein. Specifically illustratedare two groupware systems 4010 and 4020. Each system contains e-mailenables applications, 4013 and 4023, such as e-mail, schedule/calendar,word processor, spread sheet, graphics, and CTI (computer telephonyintegration). These are supported by message API's 4015, 4025 andoperating systems, 4017 and 4027, and local groupware servers 4011 and4021. Each of the local groupware servers, 4011 and 4021, has aconnector of the present invention, an e-mail server, an e-mail database, a directory server, and a replication database. The two groupwareservers 4011 and 4021 communicate over a telecommunications medium, asthe Net, a LAN, a WAN, or even the PSTN.

E-mail is by far the most common and basic groupware application. Whilethe basic technology is designed to pass simple messages between people,even relatively simple e-mail systems today typically include featuresfor forwarding messages, filing messages, creating mailing groups, andattaching files with a message. Other features that have been exploredinclude content based sorting and processing of messages, content basedrouting of messages, and structured communication (messages requiringcertain information).

Workflow systems are another element of groupware. Work flow systemsallow documents to be routed through organizations through arelatively-fixed process. A simple example of a workflow application isan expense report in an organization: an employee enters an expensereport and submits it, a copy is archived then routed to the employee'smanager for approval, the manager receives the document, electronicallyapproves it and sends it on and the expense is registered to the group'saccount and forwarded to the accounting department for payment. Workflowsystems may provide features such as routing, development of forms, andsupport for differing roles and privileges.

Hypertext is a system for linking text documents to each other, with theWeb being an obvious example. However, whenever multiple people authorand link documents, the system becomes group work, constantly evolvingand responding to others' work. Another common multi-user feature inhypertext (that is not found on the Web) is allowing any user to createlinks from any page, so that others can be informed when there arerelevant links that the original author was unaware of.

Group calendaring is another aspect of groupware and facilitatesscheduling, project management, and coordination among many people, andmay provide support for scheduling equipment as well. Typical featuresdetect when schedules conflict or find meeting times that will work foreveryone. Group calendars also help to locate people.

Collaborative writing systems may provide both realtime support andnon-realtime support. Word processors may provide asynchronous supportby showing authorship and by allowing users to track changes and makeannotations to documents. Authors collaborating on a document may alsobe given tools to help plan and coordinate the authoring process, suchas methods for locking parts of the document or linkingseparately-authored documents. Synchronous support allows authors to seeeach other's changes as they make them, and usually needs to provide anadditional communication channel to the authors as they work.

Group may be synchronous or real time, such as shared whiteboards thatallow two or more people to view and draw on a shared drawing surfaceeven from different locations. This can be used, for instance, during aphone call, where each person can jot down notes (e.g. a name, phonenumber, or map) or to work collaboratively on a visual problem. Mostshared whiteboards are designed for informal conversation, but they mayalso serve structured communications or more sophisticated drawingtasks, such as collaborative graphic design, publishing, or engineeringapplications. Shared whiteboards can indicate where each person isdrawing or pointing by showing telepointers, which are color-coded orlabeled to identify each person.

A further aspect of groupware is video conferencing. Video conferencingsystems allow two-way or multi-way calling with live video, essentiallya telephone system with an additional visual component, with timestamping for coordination.

Decision support systems are another aspect of groupware and aredesigned to facilitate groups in decision-making. They provide tools forbrainstorming, critiquing ideas, putting weights and probabilities onevents and alternatives, and voting. Such systems enable presumably morerational and evenhanded decisions. Primarily designed to facilitatemeetings, they encourage equal participation by, for instance, providinganonymity or enforcing turn-taking.

Multi-player games have always been reasonably common in arcades, butare becoming quite common on the Internet. Many of the earliestelectronic arcade games were multi-user, for example, Pong, Space Wars,and car racing games. Games are the prototypical example of multi-usersituations “non-cooperative”, though even competitive games requireplayers to cooperate in following the rules of the game. Games can beenhanced by other communication media, such as chat or video systems.

Some product examples of groupware include Lotus Notes and MicrosoftExchange, both of which facilitate calendar sharing, e-mail handling,and the replication of files across a distributed system so that allusers can view the same information.

What makes the connectors of the present invention particularlyattractive for groupware applications is the diversity of groupwareofferings and group server architectures, implementations, andplatforms. The connector of the invention can act as a front end orgateway to the groupware server.

FIG. 18 illustrates a commercial transaction where real goods areshipped from a seller to a buyer, and various forms of electronicpayment and secured electronic payment are used by the buyer to pay theseller, with banks and financial institutions connected through theconnectors described herein. Specifically, a merchant or manufacturer4101 sells a product to a customer 4103 that he has no “history” with.The product is shipped 4605. However, the buyer 4103 does not wish to beparted from his money until the goods are received, inspected, approved,and “accepted”, while the seller 4101 does not want to give up controlof the goods until he has been paid. This fundamental commercialconflict has led to various paradigms, most involving hard copy “nearmoneys” or instruments of one form or another. Today, the financialtransactions are most frequently those involving electronic fundtransfers, and electronic versions of notes, instruments, negotiableinstruments, documentary drafts, payment orders, letters of credit,warehouse receipts, delivery orders, bills of lading, including claimson goods, that is, documents of title that purport to transfer title orphysical custody of goods to the bearer or to a named person, andsecurity interests in goods. Typically, the customer 4103 executes aninstrument in favor of the seller 4101, directing the buyer's bank 4121to pay buyer's money to the seller 4101 through seller's bank 4125.Normally, this is a simple electronic transaction between buyers andsellers who have dealt with each other before, dealing through banks orfinancial intermediaries who have dealt with each other before, and whoare using the same or compatible software applications. However, in theextraordinary case where these preconditions are not satisfied, theconnectors of the invention facilitate the electronic, bank-to-bank,side of the transaction.

While the invention has been described and illustrated with respect toapplications having a single level of application program interfaces orconverters, it is, of course, to be understood that such applicationprogram interfaces or converters may be present at various levels in theprocessing hierarchy, for example between Web Clients and Web servers,between web servers and application servers, between application serversand database servers, and between application servers or databaseservers or both and various specialized repositories.

It is also to be understood, that while the invention has been describedand illustrated with respect to certain preferred embodiments andexemplification having individual clients and individual servers, theremay be multiple clients, multiple servers, and applications thatfunction as both clients and servers, as exemplified by groupwareapplications, and there might be multiple parallel lines and/or multiplehierarchical levels of application servers, data servers, and databases,as in systems for rich transactions.

While the invention has been described with respect to certain preferredembodiments and exemplifications, it is not intended to limit the scopeof the invention thereby, but solely by the claims appended hereto.

1. A method of processing an application request on an end userapplication and an application server comprising the steps of: a)initiating the application request on the end user application in afirst language with a first application program; b) transmitting theapplication request to the application server and converting theapplication request from the first language of the first end userapplication to PL/I running on the application server; c) processingsaid application request on the application server; d) transmitting aresponse to the application request from the application server to theend user application, and converting the response to the applicationrequest from the PL/I running on the application server to the firstlanguage of the first end user application; and e) wherein the end userapplication and the application server have at least one connectortherebetween, and the steps of (i) converting the application requestfrom the first language of the first end user application as a sourcelanguage to the PL/I running on the application server as a targetlanguage, and (ii) converting a response to the application request fromthe PL/I running on the application server as a source language to thefirst language of the first end user application as a target language,each comprise the steps of: 1) invoking connector metamodels ofrespective source and target languages; 2) populating the connectormetamodels with metamodel metadata of each of the respective source andtarget languages; and 3) converting the source language to the targetlanguage.
 2. The method of claim 1 wherein the end user application is aweb browser.
 3. The method of claim 2 wherein the end user applicationis connected to the application server through a web server, and the webserver comprises a connector.
 4. The method of claim 1 wherein themetamodel metadata comprises invocation metamodel metadata, applicationdomain interface metamodel metadata, and type descriptor metamodelmetadata.
 5. The method of claim 4 wherein the invocation metamodelmetadata is chosen from the group consisting of message controlinformation, security data, transactional semantics, trace and debuginformation, pre-condition and post-condition resources, and user data.6. The method of claim 4 wherein the application domain interfacemetamodel metadata comprises input parameter signatures, outputparameter signatures, and return types.
 7. The method of claim 4 whereinthe application domain interface metamodel metadata further includeslanguage metamodel metadata.
 8. The method of claim 7 wherein thelanguage metamodel metadata includes mappings between the source andtarget languages.
 9. The method of claim 8 wherein the source languageis object oriented, and the language metamodel metadata mapsencapsulated objects into code and data.
 10. The method of claim 9wherein the language metamodel metadata maps object inheritances intoreferences and pointers.
 11. The method of claim 4 wherein the typedescriptor metamodel metadata defines physical realizations, storagemappings, data types, data structures, and realization constraints. 12.The method of claim 1 wherein the transaction is a rich transactioncomprising a plurality of individual transactions, and furthercomprising processing the plurality of individual transactions on oneend user application and a plurality of application servers.
 13. Themethod of claim 12 comprising passing individual transactions amongindividual application servers.
 14. A transaction processing systemcomprising a client, a server, and at least one connector therebetween,a) the client having an end user application, and being controlled andconfigured to initiate an application request with the server in a firstlanguage with a first application program and to transmit theapplication request to the server; b) the connector being configured andcontrolled to receive the application request from the client, convertthe application request from the first language of the first end userapplication running on the client to PL/I running on the server; c) theserver being configured and controlled to receive the convertedapplication request from the connector and process the applicationrequest in PL/I with a second application program residing on theserver, and to thereafter transmit a response to the application requestthrough the connector back to the first application program on theclient; d) the connector being configured and controlled to receive theresponse to the application request from the server, to convert theresponse to the application request from the PL/I running on the serverto the first language of the first application program running on theclient; and e) wherein the connector between the client and the serveris configured and controlled to (i) convert the application request fromthe first language of the client application on the client as a sourcelanguage to the PL/I running on the server as a target language, and(ii) convert the response to the application request from the PL/Irunning on the server as a source language to the first language of theclient application running on the client as a target language, each by amethod comprising the steps of: 1) retrieving connector metamodels ofrespective source and target languages from a metamodel metadatarepository; 2) populating the connector metamodels with metamodelmetadata from the metamodel metadata repository for each of therespective source and target languages; and 3) invoking the retrieved,populated connector metamodels and converting the source language to thetarget language.
 15. The system of claim 14 wherein the end userapplication is a web browser.
 16. The system of claim 15 wherein the enduser application is connected to the server through a web server, andthe web server comprises a connector.
 17. The system of claim 14 whereinthe metamodel metadata comprises invocation metamodel metadata,application domain interface metamodel metadata, and type descriptormetamodel metadata.
 18. The system of claim 17 wherein the invocationmetamodel metadata is chosen from the group consisting of messagecontrol information, security data, transactional semantics, trace anddebug information, pre-condition and post-condition resources, and userdata.
 19. The system of claim 18 wherein the type descriptor metamodelmetadata defines physical realizations, storage mappings, data types,data structures, and realization constraints.
 20. The system of claim 17wherein the application domain interface metamodel metadata comprisesinput parameter signatures, output parameter signatures, and returntypes.
 21. The system of claim 17 wherein the application domaininterface metamodel metadata further includes language metamodelmetadata.
 22. The system of claim 21 wherein the language metamodelmetadata includes mappings between the source and target languages. 23.The system of claim 22 wherein the source language is object oriented,and the language metamodel metadata maps encapsulated objects into codeand data.
 24. The system of claim 23 wherein the language metamodelmetadata maps object inheritances into references and pointers.
 25. Thesystem of claim 14 wherein said system has a plurality of servers and isconfigured and controlled to process rich transactions.
 26. Atransaction processing system configured and controlled to interact witha client application, and comprising a server, and at least oneconnector between the server and the client application, wherein: a) theclient having an end user application, and being controlled andconfigured to initiate an application request with the server in a firstlanguage with a first application program and to transmit theapplication request to the server; b) the connector being configured andcontrolled to receive an application request from the client, convertthe application request from the first language of the first end userapplication running on the client to the PL/I running on the server; c)the server being configured and controlled to receive the convertedapplication request from the connector and process the applicationrequest in the PL/I with a second application program residing on theserver, and to thereafter transmit a response to the application requestthrough the connector back to the first application program on theclient; d) the connector being configured and controlled to receive theresponse to the application request from the server, to convert theresponse to the application request from the PL/I running on the serverto the first language of the first application program running on theclient; and e) wherein the connector between the client and the serveris configured and controlled to (i) convert the application request fromthe first language of the client application on the client as a sourcelanguage to the PL/I running on the server as a target language, and(ii) convert the response to the application request from the PL/Irunning on the server as a source language to the first language of theclient application running on the client as a target language, each by amethod comprising the steps of: 1) retrieving connector metamodelmetadata of respective source and target languages from a metamodelmetadata repository; 2) populating the connector metamodels withmetamodel metadata of each of the respective source and target languagesfrom the metamodel metadata repository and invoking the retrieved,populated connector metamodels; and 3) converting the source language tothe target language.
 27. The system of claim 26 wherein the end userapplication is a web browser.
 28. The system of claim 27 wherein the enduser application is connected to the server through a web server, andthe web server comprises a connector.
 29. The system of claim 26 whereinthe metamodel metadata comprises invocation metamodel metadata,application domain interface metamodel metadata, and type descriptormetamodel metadata.
 30. The system of claim 29 wherein the invocationmetamodel metadata is chosen from the group consisting of messagecontrol information, security data, transactional semantics, trace anddebug information, pre-condition and post-condition resources, and userdata.
 31. The system of claim 29 wherein the application domaininterface metamodel metadata comprises input parameter signatures,output parameter signatures, and return types.
 32. The system of claim29 wherein the application domain interface metamodel metadata furtherincludes language metamodel metadata.
 33. The system of claim 32 whereinthe language metamodel metadata includes mappings between the source andtarget languages.
 34. The system of claim 33 wherein the source languageis object oriented, and the language metamodel metadata mapsencapsulated objects into code and data.
 35. The method of claim 33wherein the source language and the target language are different objectoriented languages, and the language metamodel metadata mapsencapsulated code and data between the source and target languages. 36.The system of claim 33 wherein the language metamodel metadata mapsobject inheritances into references and pointers.
 37. The system ofclaim 29 wherein the type descriptor metamodel metadata defines physicalrealizations, storage mappings, data types, data structures, andrealization constraints.
 38. The system of claim 26 wherein said systemhas a plurality of servers and is configured and controlled to processrich transactions.
 39. A program product comprising a computer-readablestorage medium having invocation metamodel metadata, application domaininterface metamodel metadata, and language metamodel metadata; computerinstructions for building a metamodel metadata repository of source andtarget language metamodel metadata; and computer instructions to build aconnector for carrying out the steps of; 1) retrieving connectormetamodel metadata of respective source and target languages from themetamodel metadata repository; 2) populating the connector metamodelswith metamodel metadata of each of the respective source and targetlanguages from the metadata repository and invoking the retrieved,populated connector metamodels; and 3) converting the source language tothe target languages.
 40. The program product of claim 39 furthercomprising computer instructions for building one or more connectorstubs from said metamodel metadata.
 41. The program product of claim 39wherein the metamodel metadata in the metamodel metadata repositorycomprises invocation metamodel metadata, application domain interfacemetamodel metadata, and type descriptor metamodel metadata.
 42. Theprogram product of claim 41 wherein the invocation metamodel metadata ischosen from the group consisting of message control information,security data, transactional semantics, trace and debug information,pre-condition and post-condition resources, and user data.
 43. Theprogram product of claim 42 wherein the type descriptor metamodelmetadata defines physical realizations, storage mappings, data types,data structures, and realization constraints.
 44. The program product ofclaim 41 wherein the application domain interface metamodel metadatacomprises input parameter signatures, output parameter signatures, andreturn types.
 45. The program product of claim 41 wherein theapplication domain interface metamodel metadata further includeslanguage metamodel metadata.
 46. The program product of claim 45 whereinthe language metamodel metadata includes mappings between the source andtarget languages.
 47. The program product of claim 46 wherein the sourcelanguage is object oriented, and the language metamodel metadata mapsencapsulated objects into code and data.
 48. The program product ofclaim 46 wherein the language metamodel metadata maps objectinheritances into references and pointers.
 49. The program product ofclaim 39 wherein the source language is PL/I.
 50. The program product ofclaim 39 wherein the target language is PL/I.